Factors affecting corneal hysteresis in normal eyes

BACKGROUND: To evaluate factors affecting corneal hysteresis (CH) in normal eyes. METHODS: We examined 86 normal eyes of 43 healthy volunteers (age, 39.1 +/- 14.5 years (mean +/- standard deviation); range, 19 to 68 years; gender, 26 men, 60 women; manifest refraction, -2.25 +/- 2.89 diopters (D); range, -9.13 to 3.88 D). We quantitatively assessed the value of CH using an Ocular Response Analyzertrade mark (Reichert Ophthalmic Instruments). We carried out this measurement three times, and the average value was used for statistical analysis. Multiple regression analysis was used to assess the relevant factors of the CH. RESULTS: The mean CH was 10.2 +/- 1.3 mmHg. Explanatory variables relevant to the CH were, in order of magnitude of influence, the central corneal thickness (CCT) (partial regression coefficient B = 0.022, p < 0.0001), and the intraocular pressure (IOP) (B = -0.119, p = 0.04). No significant correlation was seen with other clinical factors such as age, gender, manifest refraction, or mean keratometric readings. CONCLUSIONS: Eyes with thinner CCT and eyes with higher IOP are more predisposed to have lower CH. Refractive surgeons should, from a biomechanical viewpoint, take not only CCT but also IOP into consideration before performing keratorefractive surgery.     

Ovarian chocolate cyst with markedly elevated serum CA19-9 level: a case report.

We report a patient with ovarian chocolate cyst with an abnormally high serum CA19-9 level (2380 U/ml) in whom MRI (Magnetic Resonance Imaging) was especially useful for the diagnosis. CA19-9 was detected in the epithelium of the chocolate cyst by the immunohistochemical technique, but it was not detected in the endometrium and adenomyotic tissue of the uterus. Twelve weeks were needed for normalization of the serum level of CA19-9 after operation.     

Structural determination of a new mutagenic heterocydic amine, 2-amino-1,7,9-trimethylimidazo[4,5-g]quinoxaline (7,9-DiMeIgQx), present in beef extract

We previously found two new mutagens, compounds I and II, inbacteriological-grade beef extract by monitoring the mutagenicityto a new Salmonella strain, YG1024; compound I was identifiedas 2-amino-4-hydroxymethyl-3,8-dimethyli-midazo[4,5-f]quinoxaline(4-CH₂OH-8-MeIQX) In the present study, we isolated compoundII from the beef extract, which accounted for 2% of the totalmutagenicity of materials adsorbed on blue cotton. Further,we found that a large quantity of compound II was produced byheating a mixture of creatine, threonine and glucose (1:1:0.5)at 200^°C for 5 h, the level being 860-fold of that in thebeef extract. The structure of this compound was determinedto be 2-amino-1,7,9-trimethylimidazo[4,5-g]quinoxaline (7,9-DiMeIgQx)by X-ray crystallography. The amount of 7,9-DiMeIgQx in bacteriological-gradebeef extract was estimated to be 53 ng/g. This compound induced13 800 and 670 revertants of S.typhimurium YG1024 and TA98 respectively,per µg in the presence of S9 mix.     

p53 Gene Mutations in Human Prostate Cancers in Japan: Different Mutation Spectra between Japan and Western Countries

The involvement of p53 mutations in prostate cancers in Japan was investigated. To evaluate any possible clinicopathological significance, p53 mutations in 40 samples from 36 Japanese prostate cancers of different stages (five cases of latent tumors, three of stage A cancers, 10 of stage B, five of stage C and 13 of stage D), including four lymph node metastases of stage D cases, were examined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and sequencing. Mutations were detected in five of 40 samples (12.5%); four were in primary cancers and the other in a lymph node metastasis from one of them. All mutation-positive cases were in stage D, and the mutation frequency in stage D cases was 31%. This result indicates that p53 mutations may play a role in the progression of a subgroup of prostate cancers in Japanese, as observed for Americans and Europeans. However, a difference was noted between Japanese and Americans in the p53 mutational spectrum (at CpG site), presumably arising from variation in the underlying etiotogic factors.     

Characterization and clinical evaluation of tumor-associated antigen CA54/61 identified by monoclonal antibodies MA54 and MA61 in epithelial ovarian cancer

Monoclonal antibodies (moABs) MA54 and MA61, directed toward the O-linked mucin-type glycoprotein, have been established and showed highly specific reactivity with human ovarian cancer. Fetal intestinal and colonic mucosal cells expressed this antigen and meconium staining was also frequently positive. To investigate the characteristic of an epitopic carbohydrate recognized by these moABs, the reactivity of each moAB with meconium extract was monitored by solid-phase enzyme-linked immunosorbent assay with mono-, di-, and oligosaccharides. MA54 and MA61 react with meconium extract and the reactivities of these moABs are neuraminidase sensitive. Ovine submaxillary mucin had a strong inhibitory activity toward the reaction between meconium extract and MA54 as well as MA61, suggesting that these moABs recognize NeuAc 2-6GalNAc epitope in meconium. The second aim of this study is to investigate the possible application of moABs to diagnose ovarian cancer and to compare these levels with those of the CA125 antigen. While serum CA54/61 antigen levels were elevated in 44.4% of ovarian cancer cases and serum CA125 antigen levels were elevated in 86.7% of the same population, the use of both assays indicated a sensitivity of detection of 97.8% (44 of 45 patients) in the population studied.     

Presence in Pieris rapae of Cytotoxic Activity against Human Carcinoma Cells

Cytotoxic activity in extracts of pupae and adults of various kinds of butterflies and moths was tested in vitro against the human gastric carcinoma cell line, TMK-1, which was chosen as an example of human carcinoma cells. Among the species examined, cytotoxicity was limited to Pieris rapae, Pieris napi and Pieris brassicae . Activity was found down to a dilution of 1/10⁴, while with the other butterflies and moths no activity was observed, even at 1/10². When the cytotoxicity of the three developmental stages, larvae, pupae and adults, of Pieris rapae was compared, the pupae showed the strongest activity, the IC₅₀ against TMK-1 cells being at the 1/10⁶ dilution. For larvae and adults, the respective IC₅₀ values were at the 1/10⁵ and 5/10⁵ dilutions. The active principle in the pupae of Pieris rapae was found to be heat-labile and not extractable with organic solvents, but precipitated with ammonium sulfate and digested by proteases, suggesting that it is a protein. This cytotoxic factor was named pierisin.     

DNA adduct formation, cell proliferation and aberrant crypt focus formation induced by PhIP in male and female rat colon with relevance to carcinogenesis

2-Amino-1-methyl-6-phenylimidazo[4, 5-b]pyridine (PhIP) inducescolon tumors in male, but not female, F344 rats, We investigatedthe mechanisms leading to this difference by measuring the levelof PhlP-DNA adducts, the enhancement of cell proliferation andaberrant crypt focus (ACF) formation in colon mucosa. PhIP wasadministered in the diet at a level of 0.04% to both male andfemale F344 rats for 1–8 weeks. The level of DNA adductsin the colon mucosa was measured using the ³²P-postlabelingmethod. Four major PhlP-DNA adducts were detected in fairlyconstant proportions in all the animals examined. The levelof PhlP-DNA adducts in male and female rats was the same, indicatingno direct correlation between adduct levels and carcinogenesis.Labeling indices (LIs) were determined by measuring BrdU incorporationin rats after feeding with a PhIP diet for 4, 8 and 12 weeks.After 8 weeks administration the LI had increased 1.5-fold inthe colon of the male rats, but no increase was observed inthe female rats. ACF formation was examined after feeding witha PhIP diet for 14 weeks. The number of aberrant crypt fociwas 6.6 ± 1.5 per rat in males and 1.9 ± 0.5 perrat in females. Thus differences in colon tumor developmentin male and female rats takes place at an early stage(s). Ourresults suggest that, in addition to DNA adduct formation, enhancedproliferation contribites to the formation of ACFs, which arepremalignant lesions of the colon.     

Presence of N2-(deoxyguanosin-8-yl)-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (dG-C8-MeIQx) in human tissues

One of the mutagenic and carcinogenic heterocyclic amines (HCAs),2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MelQx), is presentin cooked foods and we are chronically exposed to this compoundin our daily life. To study the role of HCAs in human carcinogenesis,we analyzed MelQx-DNA adducts in 38 DNA samples obtained fromsurgical and autopsy specimens by the ³²P-postlabeling methodunder adduct-intensification conditions with the modificationof additional digestion with nuclease P1 and phosphodiesteraseI after ³²P-labeling at 5' -hydroxyl termini. This modified³²P-postlabeling method can detect N²-(deoxyguanosin-8-yl)-2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline 5'-monophos-phate (5'-pdG-C8-MeIQx) at levelsdown to 1/10¹⁰ nucleo-tides. The DNA samples from colon andrectum surgical specimens and a kidney taken at autopsy werefound to contain an adduct spot corresponding to that of standard5'-pdG-C8-MeIQx on TLC at levels of 14, 18 and 1.8 per 10¹⁰nucleotides, respectively. Each adduct spot was extracted fromTLC and identified to be 5'-pdG-C8-MeIQx by HPLC. Thus, MelQx-DNAadducts actually exist in human tissues and this adduct formationmay be involved in human cancer development.     

Diverticulitis Causing a High Serum Level of Carbohydrate Antigen 19-9: Report of a Case

We report herein a rare case of diverticulitis causing a high serum level of carbohydrate antigen (CA) 19-9. A 52-year-old man was admitted to our hospital with lower abdominal pain. Laboratory data showed evidence of inflammation and a high serum level of CA 19-9 (370 U/ml). Computed tomography demonstrated thickening of the wall of the sigmoid colon. He was diagnosed as having diverticulitis of the sigmoid colon and was treated with antibiotics. Although his symptoms improved, the presence of a malignancy such as colorectal cancer could not be completely ruled out because of the persistently high serum level of CA19-9. A laparotomy was performed and the sigmoid colon was found to be adherent to the bladder. Under a diagnosis of diverticulitis, a sigmoidectomy was performed. Pathological examination revealed diverticulitis of the sigmoid colon, but there was no evidence of malignancy in the resected specimen. The serum CA19-9 level decreased to normal postoperatively and immunohistochemical staining revealed CA19-9 antigen in the cytoplasm of the diverticular epithelium. Therefore, a possible explanation for the high level of this tumor marker was diverticulitis of the sigmoid colon. Received: June 6, 2001 / Accepted: September 11, 2001