Species difference in protoporphyrin IX accumulation produced by an N-phenylimide herbicide in embryos between rats and rabbits

There was a remarkable species difference in developmental toxicity exhibited by S-53482, an N-phenylimide photobleaching herbicide, between rats and rabbits. S-53482 showed embryolethality, teratogenicity, and growth retardation in rats. In contrast, no developmental toxicity was shown in rabbits. The herbicidal activity of S-53482 is due to the photodynamic action of accumulated protoporphyrin IX (PPIX) as a result of inhibition of protoporphyrinogen oxidase (PPO), which is one of the key enzymes in porphyrin biosynthesis common to both plants and animals as part of chlorophyll and heme synthesis. Some plant PPO inhibitors were reported to inhibit mammalian PPO. Therefore, in a search for a possible link between developmental toxicity and enzyme inhibition, PPIX accumulations presumably resulting from PPO inhibition in rat and rabbit embryos were investigated. The results demonstrated that PPIX concentration was increased in rat embryos by 2 orders of magnitude when compared to that of nontreated embryos. On the other hand, no PPIX was accumulated in rabbit embryos even by treatment with a high dose level of S-53482. It was concluded that the species difference in PPIX accumulation corresponded very well to that of the developmental toxicity exhibited by S-53482.

Bufalin inhibits endothelial cell proliferation and angiogenesis in vitro

We have investigated the effects of bufalin, one of the prominent components in Chinese toad venom, on proliferation of bovine aortic endothelial (BAE) cells and tube formation in three-dimensional type I collagen matrix. In the present study, bufalin potently inhibited the formation of capillary-like tubular networks in a dose-dependent manner. Bufalin also inhibited the proliferation of BAE cells at the same concentration (5 nM) that the tube formation was inhibited. As a potent inhibitor of endothelial cell proliferation, bufalin specifically prevented the entry of BAE cells into the G0/G1 phase of a cell cycle. These findings suggest that in vitro angioinhibitory action of bufalin may be induced by the proliferation inhibition of endothelial cells through the arrest at the G2/M phase of a cell cycle.

Further study on the effects of coffee cherry on spontaneous mammary tumourigenesis in mice: effects of methanol extract

To examine the effective components in the antitumourigenic role of water extract of coffee cherry (CC), and the residue after removal of beans, the dry matter of coffee cherry was extracted repeatedly by 60% methanol and further divided into water-soluble and -insoluble fractions (CC-W and CC-M, respectively). Free access to CC-W (0.25% in tap water) markedly inhibited mammary tumour development in SHN virgin mice, while it had no effect on the growth of normal and preneoplastic mammary glands and established tumours. Associated with this, urinary excretion of some components and intrathymic T cell differentiation were stimulated by the treatment with the CC. CC-W had little affect on the endocrine system, including serum prolactin level, oestrous cycles and endocrine organs, but retarded ovarian degeneration in mice developing mammary tumours. The finding in CC-W were generally similar to those in CC. Fat emulsion of CC-M, which was only checked for mammary tumour growth owing to the limited amount available, showed no effect at the dose level used (0.25% in drinking water). Finally, the previous and the present findings taken together strongly suggest that the effective components of coffee cherry are in the water-soluble fraction.

Tumor necrosis factor-alpha (TNF alpha) enhances cisplatin cytotoxicity to ovarian carcinoma xenografts

Antitumor effect was compared between administration schedule of once a day dosing of cisplatin (DDP) for 2 consecutive days (q40d) with or without TNF alpha. In two controls, TNF alpha or dilutor alone was administered. Against the ovarian carcinoma 2008 cells, DDP given at dose level of daily x 2 (3.5 mg/kg/day q40d) combined with TNF alpha (50 mu g/kg/day) schedule showed 6.08-fold tumor growth delay (TGD) (17.10+/-1.65; P<0.01), produced 3.17-fold greater cell kill [ratio of tumor volume of treated and control groups (T:C)=0.148; P<0.01] and resulted in longer survival [median survival (MS)=166; P<0.01] than DDP alone. These are superior to even high dose DDP (7.0 mg/kg/day x 2d) without TNF alpha administration schedule showing TGD=11.38 days T:C=0.271 and MS=97 days. High dose DDP (7.0 mg/kg/day q40d) with TNF alpha showed further DDP antitumor potency (TGD=29.74+/-2.08, P<0.01), however, this schedule showed only 2.56-fold TGD extension and no improvement was found in survival because of its severe toxicity. TNF alpha did not alter DDP induced systemic toxicity. These data indicate that optimal antitumor activity, tolerance and survival improvement occured on a schedule of low dose DDP combined with TNF alpha, and this has prompted the clinical evaluation of this administration schedule.

Histological changes in rat embryonic blood cells as a possible mechanism for ventricular septal defects produced by an N-phenylimide herbicide

An N-phenylimide herbicide, S-53482, inhibits protoporphyrinogen oxidase, an enzyme common to chlorophyll and heme biosynthesis, and produces embryolethality, teratogenicity [mainly ventricular septal defects (VSD) and wavy ribs], and growth retardation in rats. In order to elucidate the mechanism of the developmental toxicity, in particular VSD, effects of the herbicide on rat embryonic blood cells were investigated histologically at the light and electron microscopic levels at 6, 12, 24, 36, and 48 h after oral administration of the chemical to pregnant rats on day 12 of gestation, the most sensitive day for toxicity. Electron and light microscopy demonstrated mitochondrial lesions, including abnormal iron deposits that were probably due to inhibition of heme biosynthesis, in erythroblasts derived from the yolk sac. Subsequently, degeneration of these erythroblasts occurred followed by erythrophagocytosis. Histologically hearts from exposed embryos had a thin ventricular wall, which may reflect a compensatory reaction to a loss of embryonic blood cells. Thus, the herbicide may induce VSD due to hematological dysfunction caused by the inhibition of heme biosynthesis rather than by direct injurious effects on the heart.

Renal pelvic and ureteral carcinoma with huge hydronephrosis: US, CT, and MR findings

A 78-year-old man presented huge hydronephrosis with a calculus in the left kidney, and underwent left nephroureterectomy under the diagnosis of renal pelvic and ureteral tumor. Histological examination disclosed renal pelvic and ureteral tumors featuring mixed histologic types of carcinoma. Magnetic resonance (MR) imaging was superior to computed tomography (CT) in its complete, detailed demonstration of the renal pelvic lesions. The imaging characteristics of CT, MR imaging, ultrasonography, and retrograde ureterography were discussed in the report.

Oesophageal cancer coexisting with colorectal lesions

OBJECTIVE

To investigate the incidence of colorectal lesions in patients who present with oesophageal cancer.

DESIGN

Prospective open study.

SETTING

University hospital, Japan.

SUBJECTS

135 of 218 patients who presented with squamous cell carcinoma of the oesophagus during the seven year period 1988-1994 were randomly allocated to have a barium enema examination.

INTERVENTIONS

Barium enema examinations, and if colorectal lesions were found, colonoscopy and biopsy.

MAIN OUTCOME MEASURE

Incidence of coexistent colorectal lesions.

RESULTS

No abnormal findings were found in 52 (39%), diverticula were present on 37 (27%), benign polypoid lesions in 51 (38%), and malignant lesions in 6 (4%). We examined the clinical and histopathological details of all patients to see if it was possible to distinguish the patients at high risk of developing oesophageal and colorectal cancer but could find no differences among the groups.

CONCLUSION

Asymptomatic colorectal lesions are relatively common in patients with squamous cell carcinoma of the oesophagus in Japan.

Prevalence of Mycoplasma genitalium in men with gonococcal urethritis

A significant association of Mycoplasma genitalium with non-gonococcal urethritis has been reported, but the prevalence of this mycoplasma in men with gonococcal urethritis has not been so well studied. In this study, we examined urethral swab specimens from 45 Japanese male patients with gonococcal urethritis for the presence of M. genitalium by using a polymerase chain reaction-based assay. We also sought Chlamydia trachomatis by an enzyme immunoassay (Chlamydiazyme). Of the 45 specimens, 2 (4.4%) were positive for the mycoplasma and 12 (26.7%) were positive for C. trachomatis. The findings suggest that M. genitalium may be a cause not only of non-gonococcal urethritis but also of postgonococcal urethritis.

Rapid detection of point mutations of the Neisseria gonorrhoeae gyrA gene associated with decreased susceptibilities to quinolones

Mutations in the gyrA gene resulting in amino acid changes at Ser-91 and Asp-95 are significantly associated with decreased susceptibilities to quinolones in Neisseria gonorrhoeae. To detect these mutations, we developed a rapid and simple assay based on amplification of the region of the gyrA gene containing the mutation sites by PCR and digestion of the PCR product with a restriction enzyme. A naturally occurring HinfI restriction site was present in the region containing the Ser-91 codon, and an artificial HinfI restriction site was created in the region containing the Asp-95 codon by the method of primer-specified restriction site modification. The mutations generating alterations at Ser-91 and Asp-95 were detected as restriction fragment length polymorphisms of the PCR products digested with HinfI. Fifty-five clinical strains of N. gonorrhoeae were examined for mutations in the gyrA gene by this method. Mutations at Ser-91 and/or Asp-95 were detected in all the 31 strains in which the mutations had been confirmed by DNA sequencing. Our method allows simultaneous testing of a large number of strains and provides results within 8 h. This rapid and simple assay could be a useful screening device for genetic alterations associated with decreased susceptibilities to quinolones in N. gonorrhoeae and could facilitate epidemiological studies on clinical isolates of N. gonorrhoeae with decreased susceptibilities to quinolones.

Lateral lunate morphology: an x-ray study

The lunate has been described by Kauer as being thinner dorsally than volarly when measured proximal to distal. We used an x-ray method to measure the shape of the lunate in order to compare dorsal and volar thicknesses after recognizing clinically a group of patients with scapholunate dissociation in whom volar flexed lunates were present. Using this method, 292 standard lateral views of the lunate were collected randomly and measured. The shape of the lunate could be classified into 3 types: type D lunates have a thinner dorsal segment and correspond to Kauer's description; type V lunates have a thinner volar segment; type N lunates have equal dorsal and volar segments. There were 196 type D lunates (67%), 67 type V lunates (23%), and 29 type N lunates (10%). The radiolunate angles were measured in a random selection from type D and type V lunates to determine any relationship between the volar segment to dorsal segment thickness (wedge) ratio. No relationship within these groups was identified. However, there was a significant difference in the radiolunate angles between these two groups. Recognition of the prevalence of the type V lunate alters concepts proposed by Kauer and warrants further investigation of factors influencing lunate position.

Idebenone improves cerebral mitochondrial oxidative metabolism in a patient with MELAS

We report a 36-year-old man with MELAS in whom a 5-month course of high-dose oral idebenone, a derivative of coenzyme Q10, increased markedly cerebral metabolic ratio of oxygen and oxygen extraction fraction without increased cerebral blood flow with PET. The results indicate that idebenone improves mitochondrial oxidative metabolism in the brain and suggest a therapeutic potential of idebenone for MELAS.

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.

Effects of coffee cherry on the immune system in SHN mice

Previously, we found that chronic ingestion of the extract of coffee cherry (CC), the residue after the removal of coffee beans, induced a marked suppression of the development and the growth of spontaneous mammary tumours in a high mammary tumour strain of SHN mice. As a possible step to clarify the mechanism of this effect, the immunomodulating role of CC was examined in this study. CC treatment resulted in significant weight gain in the spleen. CC treated experimental mice showed a significant decrease in the proportion of immature (CD4+8+) thymocytes and an increase in the percentages of mature cells expressing helper/inducer (CD4+8-) or cytotoxic/suppressor (CD4-8+) phenotypes. The proportion of T cells expressing CD25, a lymphocyte activation marker, in the spleen and peripheral blood tended to increase in the CC treated group. The natural killer activity of the spleen cells was not affected by CC ingestion. These results have revealed that CC can enhance the differentiation of thymocytes and the activation of peripheral T lymphocytes.

Sequence analysis of the genome of the unicellular cyanobacterium Synechocystis sp. strain PCC6803. II. Sequence determination of the entire genome and assignment of potential protein-coding regions

The sequence determination of the entire genome of the Synechocystis sp. strain PCC6803 was completed. The total length of the genome finally confirmed was 3,573,470 bp, including the previously reported sequence of 1,003,450 bp from map position 64% to 92% of the genome. The entire sequence was assembled from the sequences of the physical map-based contigs of cosmid clones and of lambda clones and long PCR products which were used for gap-filling. The accuracy of the sequence was guaranteed by analysis of both strands of DNA through the entire genome. The authenticity of the assembled sequence was supported by restriction analysis of long PCR products, which were directly amplified from the genomic DNA using the assembled sequence data. To predict the potential protein-coding regions, analysis of open reading frames (ORFs), analysis by the GeneMark program and similarity search to databases were performed. As a result, a total of 3,168 potential protein genes were assigned on the genome, in which 145 (4.6%) were identical to reported genes and 1,257 (39.6%) and 340 (10.8%) showed similarity to reported and hypothetical genes, respectively. The remaining 1,426 (45.0%) had no apparent similarity to any genes in databases. Among the potential protein genes assigned, 128 were related to the genes participating in photosynthetic reactions. The sum of the sequences coding for potential protein genes occupies 87% of the genome length. By adding rRNA and tRNA genes, therefore, the genome has a very compact arrangement of protein- and RNA-coding regions. A notable feature on the gene organization of the genome was that 99 ORFs, which showed similarity to transposase genes and could be classified into 6 groups, were found spread all over the genome, and at least 26 of them appeared to remain intact. The result implies that rearrangement of the genome occurred frequently during and after establishment of this species.

Oesophageal cancer composed of mixed histological types

Glandular or adenoid cystic differentiation and sarcomatous features are sometimes encountered in oesophageal cancer and such histological variants often coexist with ordinary squamous cell carcinoma. So far no serial evaluation of such mixed histological types of oesophageal cancer has ever been performed, we therefore clinicopathologically investigated such cases While an immunohistochemical study of the p53 protein was also done on four available cases in order to discuss the histogenesis of these tumours. Among the 600 patients with surgically resected oesophageal cancer, seven cases were found to have a mixture of histological variants with ordinary SCC (squamous cell carcinoma) (adenocarcinoma 1, adenoid cystic cancer 3, sarcomatous component 2, basaloid cystic cancer and sarcomatous component 1). All but one case had an elevated type tumour while the predominant components of protrusion were not SCC but variant histological types. Six tumours were restricted to the submucosal layer. An immunohistochemical study of the p53 protein revealed that two of four cases were positive in both the SCC and variant patterns. Mixed histological types of oesophageal cancer composed of SCC and other variants often occur and thus the carcinogenesis of both histological types are considered to be aspects of the same mechanism.

[Intermediate filaments]

The antibodies for intermediate filaments, including keratin, vimentin, desmin, GFAP and neurofilaments, have been much useful in routinely-processed immunohistochemical study for identifying characteristics of tumor cells or making the definite diagnosis. In general, when neoplastic transformation has taken place, the affected cells would reveal to some extent alterated immunolocalization of intermediate filaments in the cytoplasm. Whether the tumor cells are of epithelial or non-epithelial origin is significant from diagnostic points of view when utilizing those intermediate filaments as tumor markers. But there are many "exceptional" cases of epithelial tumors with expression of vimentin, or those of non-epithelial tumors with expression of keratin, indicating some "variants". Immunohistochemical application of the intermediate filaments is indispensable not only as "a diagnostic tool for surgical pathologists", but also a method for analyzing relationship between morphological changes and functional aspects of the tumor cells.

Syndrome of inappropriate secretion of antidiuretic hormone in elderly patients with rheumatoid arthritis associated with infections: report of two cases

Two rheumatoid arthritis (RA) patients with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) during the course of infection are herein reported. One patient developed SIADH during the course of a localized cutaneous herpes zoster infection while the other developed SIADH in conjunction with Staphylococcus simulans septicemia. We consider that the development of SIADH was strongly associated with superimposed infections in the underlying RA. This is the first report discussing the association of SIADH and infections in RA patients in which SIADH is diagnosed by measurement of plasma ADH.

Mutations in the p53 gene and human papillomavirus infection as significant prognostic factors in squamous cell carcinomas of the oral cavity

The p53 gene has been indicated to be a tumour suppressor gene that is found in mutated form in common human cancers. Human papillomavirus (HPV) has oncogenic activity in cervical and oral squamous cell carcinomas (SCCs). The E6 protein of HPV is known to bind with p53 protein and inactive the tumor suppressor activity by promoting p53 degradation. Because of this background, we examined 38 primary, resected specimens of oral SCCs for detection of p53 mutations and HPV DNAs. Exons 5 through 8 of the p53 Mutations were observed in nine cases (24%). HPV-DNA detection and typing were performed using PCR with ¿high risk group' HPV-specified primers. HPV DNA sequences were detected in eight cases (21%). The AvaII digestion pattern of PCR-amplified HPV DNA showed that HPV-16 was present in all eight cases. Seven cases were p53 mutation-positive/HPV-negative, six cases were p53 mutation-negative/HPV-positive, and two intraosseus SCC cases were p53 mutation-positive/ HPV-positive. Thus, 15/38 (40%) cases had inactivation of the p53 protein. Interestingly, p53 mutation-negative/ HPV-negative cases had a poorer prognosis than p53 mutation positive or HPV-positive cases (P < 0.01). We conclude that (1) mutation in the p53 gene and/or HPV infection are frequent (40%) in oral SCC; (2) inactivation of p53 function by mutation and HPV infection are important genetic events in the development of 40% integral of oral SCCs; (3) p53 mutation and HPV infection are not mutually exclusive events and (4) other oncogenes or tumor suppressor genes may be crucial in the development of oral SCC if the prognosis is poor.

What is the earliest malignant lesion in the esophagus?

BACKGROUND

The incidence of early esophageal cancer is definitely increasing due to recent advances in diagnostics. When we discuss early carcinoma of the esophagus, however, there is still controversy as to whether dysplasia is either benign or the earliest malignant lesion.

METHODS

Nineteen resected esophaguses with both cancer and dysplasia (including 19 cancers concomitant with 26 dysplastic lesions) were studied for expression of p53 protein.

RESULTS

Immunohistochemical overexpression of p53 protein in esophageal dysplasia is almost the same as that in cancer.

CONCLUSIONS

Esophageal dysplasia should be recognized as the earliest malignant lesion which already demonstrates cancerous features although it is not immediately critical. A routine endoscopic Lugol's solution test is very useful for both detection and following-up of the early nests in the esophagus. These lesions are good candidates for endoscopic mucosal resection for the purpose of accurate diagnosis or curative treatment.