[A patient with gastric cancer with para-aortic lymph node metastases surviving for 9 years after effective preoperative chemotherapy and radical operation]

A 63-year-old male patient with type 3 advanced gastric cancer was referred to our hospital. Preoperative examination by CT-scan revealed swollen para-aortic lymph nodes and cancer invasion to the pancreas. The patient was treated pre-operatively with intravenous 5-FU, 500 mg/body/day, continuous infusion for 1 week. Immediately after the chemotherapy, the patient underwent total gastrectomy, splenctomy, left-adrenectomy and resection of the body and tail of the pancreas, along with para-aortic lymph node dissection. Microscopic examination revealed that the tumor was a moderately differentiated tubular adenocarcinoma, which displayed invasion to the pancreas with lymph node metastasis up to the level 3 lymph node. Histologically, the effect of preoperative chemotherapy showed a grade 2 effect on the main tumor, but a grade 3 chemotherapeutic effect was observed at the para-aortic lymph nodes. The patient has subsequently remained disease free for 9 years. In this case, it is considered that the preoperative chemotherapy by 5-FU and potentially curative radical operation yielded a good outcome.

5-fluorouracil sensitivity and dihydropyrimidine dehydrogenase activity in advanced gastric cancer

BACKGROUND

Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme of 5-fluorouracil (5-FU) catabolism. Several studies have demonstrated the clinical importance of DPD in cancer patients, suggesting that the efficacy of 5-FU may be related to DPD activity in tumor tissue. In the present study, DPD activity and chemosensitivity to 5-FU were evaluated in advanced gastric cancer.

MATERIALS AND METHODS

Thirty-four gastric cancers from 32 patients were studied and chemosensitivity to 5-FU was evaluated by histoculture drug response assay.

RESULTS AND CONCLUSION

DPD activity and tumor inhibition of 5-FU among all cases showed no significant correlation, but among 14 histologically differentiated cases significant correlation was observed. DPD activity may be useful in determining the 5-FU sensitivity of differentiated gastric cancer.

Treatment strategy for pancreatic head cancer: pylorus-preserving pancreatoduodenectomy, intraoperative radiotherapy and portal catheterization

Pancreatic cancer is the disease of gastrointestinal cancer with the poorest prognosis. At present, in addition to surgery, multimodality treatment combining a variety of therapeutic methods is used. We usually employ the following combination of surgery, radiotherapy and chemotherapy: D2 surgery with pylorus-preserving pancreatoduodenectomy (PPPD), intraoperative radiotherapy (IORT), and portal catheterization (PC) with fluorouracil as the chemotherapy. In this study, we made a historical comparison of PPPD and PD and obtained the following findings: (1) PPPD allows almost the same extent of D2 dissection as conventional PD, and achieves radical treatment without any problems; (2) suppression of local recurrence by IORT cannot be expected from the results of the comparison between the four approaches, i.e. surgery alone, surgery + IORT, surgery + PC and surgery + IORT + PC, and (3) the rate of liver metastasis in patients treated by PC was significantly low.

Expression of MTA1, a metastasis-associated gene with histone deacetylase activity in pancreatic cancer

MTA1 has been identified as a metastasis-promoting gene, and its gene expression is correlated with serosal invasion and lymph node metastasis in the gastrointestinal and esophageal cancers. We examined MTA1 mRNA expression levels in 13 cell lines and 23 tumor tissues of pancreatic cancer by quantitative reverse transcription polymerase chain reaction. MTA1 mRNA expression was found in all the cell lines, however its levels were not correlated with the metastatic pontential of each cell line representing hematogenous distant metastasis. In the pancreatic cancer tissues, the overexpression of MTA1 mRNA (tumor/normal ratio >/=1) was observed in 12 out of 23. Pancreatic cancer tissues overexpressing MTA1 mRNA (T/N ratio >/=1) tended to have higher incidence of lymph node metastasis. These results together with previous findings in the gastrointestinal and esophageal cancers suggest that MTA1 might be involved in the progression, particularly in lymph node metastasis of pancreatic cancer.

Activation of NFkappaB is necessary for IL-1beta-induced cyclooxygenase-2 (COX-2) expression in human gingival fibroblasts

The immediate-early cyclooxygenase-2 (COX-2) gene encodes an inducible prostaglandin synthase enzyme which is implicated in inflammatory and proliferative diseases. COX-2 is highly induced during cell activation by various factors, including mitogens, hormones and cytokines. Since pro-inflammatory cytokine IL-1beta has been shown to induce prostaglandin E2 (PGE2) release in human gingival fibroblasts (HGF), here we analyzed the effect of IL-1beta on the expression of COX-2 and the activation of NFkappaB in HGF. Northern hybridization analysis revealed that IL-1beta (200 pg/ml) increased the expression of COX-2 mRNA in HGF. The effect of IL-1beta was abrogated by herbimycin A, a protein tyrosine kinase inhibitor, and enhanced by orthovanadate, a protein tyrosine phosphatase inhibitor. IL-1beta-induced PGE2 release was blocked by the tyrosine kinase inhibitor and increased by the tyrosine phosphatase inhibitor. The results of transient transfection assays using chimeric constructs of the human COX-2 promoter (nt -1432 approximately +59) ligated to a luciferase reporter gene indicated that IL-1beta stimulated the transcriptional activity approximately 1.5-fold. Gel mobility shift assays with a radiolabelled COX-2-NFkappaB oligonucleotide (nts-223 to-214) revealed an increase in the binding of nuclear proteins from IL-1beta-stimulated HGF. This increase of DNA-protein complex formation induced by IL-1beta was blocked by herbimycin A and another tyrosine kinase inhibitor, genistein. These results suggest that NFkappaB is an important transcription factor for IL-1beta-induced COX-2 gene expression, and is involved in inducing COX-2 gene transcription through tyrosine phosphorylation in HGF.

Chronic unilateral ureteral obstruction represented as renin-dependent hypertension

A 50-year-old woman developed renin-dependent hypertension immediately after accidental unilateral ureteral ligation during hysterectomy, and the hypertension lasted for 5 months. Surgical release of the obstruction was carried out 157 days after the ligation. Then, her blood pressure was normalized. However, the obstructed kidney showed intensive tubulointerstitial fibrosis and functional recovery was not obtained. This case suggests that the renin-angiotensin system may be upregulated in human kidney during unilateral ureteral obstruction for a long duration.

Bradykinin potentiates prostaglandin E(2) release in the human gingival fibroblasts pretreated with interleukin-1beta via Ca(2+) mobilization

Interleukin-1beta, a proinflammatory cytokine, causes a slow increase in prostaglandin E(2) release. On the other hand, bradykinin, a chemical mediator for inflammation, induces a rapid prostaglandin E(2) release. Simultaneous stimulation with interleukin-1beta (200 pg/ml) and bradykinin (1 microM) evoked a moderately synergistic increase in prostaglandin E(2) release in human gingival fibroblasts. However, in the human gingival fibroblasts pretreated with interleukin-1beta, bradykinin drastically enhanced prostaglandin E(2) release. NS-398, a specific inhibitor of cyclooxygenase-2, inhibited not only interleukin-1beta-induced prostaglandin E(2) release but also bradykinin-induced prostaglandin E(2) release in the human gingival fibroblasts pretreated with interleukin-1beta. Transcriptional and translational inhibitors such as actinomycin D, cycloheximide, and dexamethasone also suppressed the interleukin-1beta-induced prostaglandin E(2) release and the bradykinin-induced prostaglandin E(2) release in interleukin-1beta-pretreated human gingival fibroblasts. In the fibroblasts pretreated with interleukin-1beta, Ca(2+)-mobilizing reagents such as ionomycin and thapsigargin mimicked the potentiating effect of bradykinin on prostaglandin E(2) release. These results suggest that interleukin-1beta- and bradykinin-induced prostaglandin E(2) release is dependent on cyclooxygenase-2 and the potentiated effect of bradykinin in the human gingival fibroblasts primed with interleukin-1beta is caused by Ca(2+) mobilization.

[Subjective burdens of families caring for "frail elderly" in their homes]

The purpose of the study is to measure the subjective burdens of families caring for "frail elderly" in their homes and to clarify the relationships between caregivers' subjective burdens and the health conditions of the "frail elderly", the family's conditions, the use of social services and availability of social supports. The subjects consisted of caregivers of the elderly who also were using nursing services from K Home Visit Nursing Care Station (K-Station). We mailed subjective burden questionnaires to 98 families among users of K-Station from December of 1994 to March of 1995. We used the 12 items developed by Nakatani as a scale to measure subjective burdens. Each item was stratified into 4 grade levels from "agree" to "disagree". We asked nurses at K-Station about "frail elderly" ADL conditions in detail, the extent of medical dependency and the will of families to care for the elderly. A total of 76 questionnaires were returned, of which 73 could be analyzed. The greater part of "frail elderly" were female (n = 42). The average age of the "frail elderly" was 81.1(+/- 7.6) years old. All caregivers were members of the family of the "frail elderly" and most of them were women (n = 63). From the result of principal analysis, 2 principles were extracted from the 12 items used to measure subjective burden of caregivers. We analyzed the first principle as "subjective burden of caregivers". From the result of multiple regression analysis (Stepwise method), "subjective burden of caregivers" was characterized by the caregivers' conditions only (caregivers' health status, the will to care for the elderly and anxiety of providing night care). This result suggested that support for the caregivers of the "frail elderly" was important to sustain in-home care.

Combined resection of the portal vein for pancreatic cancer: preoperative diagnosis of invasion by portography and prognosis

BACKGROUND/AIMS

Pancreatic cancer often invades the portal vein because of the anatomical position. Pancreatic cancer with portal vein invasion was not considered operable, and thus the resectability rate was low.

METHODOLOGY

Between March 1976 and February 1994, 140 of 243 patients underwent resection, a resectability rate of 58%. A total of 81 (58%) of these patients underwent portal vein resection. We assessed 56 patients in whom the depth of invasion had already been determined histopathologically and whose superior mesenteric arterial portograms were readable. The 56 patients were classified into 4 groups: normal (Type I), stricture on one side of the portal vein (Type II), stricture on both sides of the portal vein (Type III), complete obstruction (Type IV). The length of the longitudinal lesions on portograms was also measured.

RESULTS

In 93% (27/29 cases) of portographic Type I or II lesions with longitudinal lesions of 2 cm or less, portal vein invasion was limited to the tunica media. No patients with cancer invasion into the lumen survived more than 1 year.

CONCLUSIONS

For patients with pancreatic cancer Type I or II, preoperative portography findings and longitudinal lesions of 2 cm or less, portal vein resection is indicated, and long-term survival can be expected.

CALNUC (nucleobindin) is localized in the Golgi apparatus in insect cells

A mouse monoclonal antibody 12B1 was raised against Golgi fractions from Sf21 insect cells and selected as Golgi-specific by immunostaining of the cells. The antigen was purified from the cells by immunoaffinity chromatography with the monoclonal antibody, and its N-terminal and internal amino acid sequences were determined. Based on the partial amino acid sequences, cDNA encoding the antigen protein was cloned and sequenced. The amino acid sequence deduced from the cDNA nucleotide sequence showed a homology to those of CALNUC family proteins, CALNUC (or nucleobindin, a calcium-binding Golgi protein with DNA-binding activity) and protein NEFA (a cell surface protein with DNA-binding, EF-hand, and acidic domains). The insect protein had two EF-hand loops at the same sites as the mammalian CALNUC family proteins, but had no leucine zipper which the mammalian homologues commonly have. An electron microscopic immunoperoxidase study demonstrated that the insect protein was localized in the cis-Golgi cisternae and cis-Golgi networks. Since this localization is identical to that of mammalian CALNUC, the insect protein was considered to be a homologue of CALNUC rather than that of NEFA. Assays involving proteinase K digestion, sodium carbonate extraction and Triton X-114 extraction revealed that the insect CALNUC-like protein was a soluble protein tightly associated with the luminal surface of Golgi membranes as reported for mammalian CALNUC. The insect protein was also shown to have calcium-binding activity as does mammalian CALNUC. These data verify that the insect protein is CALNUC. The existence of CALNUC in insect cells suggests that CALNUC is an essential calcium-binding Golgi protein in a wide range of the animal kingdom. A phylogenetic tree analysis, however, suggested that NEFA was derived from CALNUC long after the segregation of a mammalian ancestor from an insect ancestor.

[Difficulty in using RP, PL, and EW factors in the Japanese classification of pancreatic carcinoma]

The classification of pancreatic carcinoma by the Japan Pancreas Society reflects the prognosis of each stage better than does the TMN classification. On the other hand, there are too many factors to examine in the Japanese system, some of which are difficult to use and have low accuracy in pre- and/or intraoperative diagnosis (RP and PL), and their analysis requires various specimen handling procedures (EW). We propose that: 1) a simple, easy decision flow chart be established for ew and 2) EW/ew be designated as (-) or (+) and for EW/ew (+) cases other factors (ly, v, pl, and direct tumor invasion) be added (for example, ew (+)-pl).

[mRNA expression of chemokines in rat kidneys with ureteral obstruction]

BACKGROUND

It has been demonstrated that leukocyte infiltration, mainly of macrophages and lymphocytes, into obstructed kidneys (OBK) of rats during unilateral ureteral obstruction (UUO). Chemokines (C-C subfamily) may be involved in this mechanisms. Thus, we accessed the gene expression of chemokines in renal cortex of rats with UUO.

MATERIALS AND METHODS

Female SD rats were sacrificed at various time points after UUO. mRNA expression of MCP-1, RANTES and MIP-1 alpha was determined by semi-quantitative RT-PCR.

RESULTS

Control kidneys (CNK) showed a weak mRNA expression of MCP-1, RANTES and MIP-1 alpha. OBKs showed an increase in MCP-1 at 2 hours of UUO and a significant increase at 4 hours of UUO as compared with CNKs or contralateral unobstructed kidneys (CLK). The mRNA levels of RANTES and MIP-1 alpha were not increased until 72 hours of UUO in CLKs or OBKs. There were slight, but significant, differences of RANTES and MIP-1 alpha expression between OBKs and CNKs at 120 hours of UUO.

CONCLUSIONS

We suggest that the early increase in MCP-1 contributes to the leukocyte infiltration and that RANTES and MIP-1 alpha plays a partial role in a late increases.

Increased expression of TGF-beta1 but not of its receptors contributes to human obstructive nephropathy

Increased expression of TGF-beta1 but not of its receptors contributes to human obstructive nephropathy.

BACKGROUND

Previous studies have revealed an increased expression of transforming growth factor-beta1 (TGF-beta1) and deposition of extracellular matrix in the kidney of animals with ureteral obstruction. However, these relationships have not been elucidated in the hydronephrotic kidney of humans.

METHODS

We analyzed the tissue expression of extracellular matrix proteins, TGF-beta1, and its receptors in the human kidney with ureteral obstruction by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Obstructed kidneys (OBKs) were obtained from patients with ureteral tumors. A kidney specimen from patients with a renal tumor was used as control (CNKs).

RESULTS

The interstitial volume was significantly increased in OBKs in comparison with CNKs. OBKs showed increased deposition of collagen types I and IV and fibronectin in the renal interstitium. RT-PCR revealed overexpression of collagen alpha1(IV) mRNA and fibronectin mRNA in OBKs. OBKs showed a significantly increased mRNA expression of TGF-beta1 in comparison with CNKs. The immunoreactivity for TGF-beta1 increased markedly in the interstitium of OBKs. There was a significant correlation between the TGF-beta1 mRNA level and the interstitial volume. However, there was no significant difference between OBKs and CNKs in the relative mRNA level nor in immunoreactivity for TGF-beta receptors.

CONCLUSIONS

These data suggest that TGF-beta1 may contribute to the interstitial fibrosis found in the human kidney with ureteral obstruction, mainly because of an increase in the expression of this cytokine without significant changes to its receptors.

Evaluation of pylorus-preserving pancreatoduodenectomy with the Imanaga reconstruction by hepatobiliary and gastrointestinal dual scintigraphy

BACKGROUND

Following pylorus-preserving pancreatoduodenectomy (PPPD), most surgeons use gastrointestinal reconstruction with an end-to-side duodenojejunostomy placed distally to the pancreatojejunostomy and choledochojejunostomy. In contrast, the authors have consistently used PPPD with the Imanaga reconstruction (PPPD-Imanaga) which consists of end-to-end duodeno- jejunostomy, end-to-side pancreatojejunostomy and choledochojejunostomy, performed in that order. In this study, the movement of bile and food after PPPD-Imanaga was evaluated to document the functional advantages of this method.

METHODS

Twenty-four patients who had undergone PPPD-Imanaga were subjected to hepatobiliary and gastrointestinal dual scintigraphy. The interval between operation and scintigraphy ranged from 28 days to 67 months. Six of the 24 patients underwent repeated dual scintigraphy for the observation of temporal changes in gastrointestinal function.

RESULTS

The incidence of biliogastric reflux and bile stasis in the jejunal loop was markedly decreased at times later than 2 months after operation. Delay of gastric emptying and bile evacuation, sometimes accompanied by stasis in the jejunal loop, affected the mixing status of bile and food at 1 h after the beginning of imaging. A majority of the patients, however, had a satisfactory mixing status at 2 h.

CONCLUSION

The Imanaga reconstruction appears to be a recommendable procedure following PPPD, in light of the bile and food movement achieved in the gastrointestinal tract.

Intrauterine growth retardation as a cause of perinatal mortality in Japanese black beef calves

Perinatal death is one of the major causes of calf mortality in Japanese Black beef herds. A series of experiments were carried out to determine causes of perinatal calf mortality in a region of northern Japan. An aetiological survey revealed that the incidence of perinatal mortality in 6475 calves was 4.5% and the majority of neonatal deaths were caused by weak calf syndrome. The weak calves delivered after a normal gestation period had a significantly lower body weight at birth than normal calves (P < 0.01), indicating growth retardation in the uterus during pregnancy. Haematological and histopathological examinations showed that the weak calves had anaemia characterized by a significant decrease of blood cell values and bone marrow hypofunction. The anaemia due to bone marrow hypofunction presumably caused intrauterine growth retardation of the foetus. Dams delivering the weak calves showed significantly lower serum concentrations of estrone sulphate during late pregnancy than those with normal calves (P < 0.01), indicating foeto-placental dysfunction as a possible cause of growth retardation. Effects of sires as well as the maternal family on the incidence of neonatal death and on the rate of weak calves in dead neonates were found in the survey. Intrauterine growth retardation associated with anaemia may be the most important cause of weak calf syndrome in Japanese Black beef calves. The bull and maternal family may also have an influence on the incidence of neonatal death.

[A follow-up study on effects of ADL deterioration on QOL in patients with neurological intractable diseases]

OBJECTIVE

This follow-up study examined correlating factors, including change of activity of daily living (ADL), which are associated with subjective quality of life (QOL) in patients with neurological intractable diseases such as amyotrophic lateral sclerosis, spinocerebellar degeneration and Parkinson disease.

METHODS

Baseline information of 159 patients with above mentioned three intractable diseases registered by two public health centers in Niigata and Fukuoka Prefectures was obtained in 1993-1994, and they were followed to 1995. At the end of follow-up, 124 subjects were interviewed by public health nurses using the 27 item-subjective QOL scale for patients with neurological intractable diseases, previously confirmed for reliability and validity.

RESULTS

Low level of ADL at the time of registry and deterioration of ADL after the registry were independently related to low level of subjective QOL.

CONCLUSIONS

It may be necessary to minimize the ADL deterioration, in order to maintain a high subjective QOL of patients with neurological intractable diseases.

Stirring system for radioactive waste water storage tank

A stirring system for 100-m(3) radioactive liquid waste tanks was constructed to unify radioactive concentrations in the tank. The stirring system is effective in certifying that the radioactive concentrations in the tanks are less than the legal limits before they are drained away as waste liquid. This system is composed of discharge units, pipe lines, and a controller. The performance of the system was assessed by comparing the calculated red ink and 32P concentrations with those monitored at six locations in the tanks. The concentration reached equilibrium after stirring 60 to 120 min with discharge units equipped with six fixed openings configured in differing directions. Residual chlorine in city water used for dilution occasionally bleached the red ink and reduced its concentration. The adsorption of 32P by slime on the walls of the tanks storing actual waste water lowered the equilibrium concentration.

Comparison of vestibular and cochlear ototoxicity from transtympanic streptomycin administration

HYPOTHESIS

The relative dose-related cochlear and vestibular ototoxicity produced by transtympanically injected streptomycin (SM) compared to that of gentamicin (GM) was assessed.

BACKGROUND

Although SM, the first aminoglycoside used transtympanically, is thought to be selectively vestibulotoxic, it has been replaced by GM in current clinical use. Little experimental data exist that directly demonstrate the relative cochlear and vestibular ototoxicity resulting from transtympanic administration of SM compared to GM.

METHODS

Histologic evaluation was performed on inner ears from Mongolian gerbils to study vestibular and cochlear damage. Comparisons were made between animals receiving single (1 x SM) and five daily (5 x SM) injections of SM/Gelfoam-slurry and similarly injected and noninjected controls. These data were compared to results obtained using GM (1 x GM and 5 x GM) reported previously.

RESULTS

Two weeks after injection, parallel qualitative and quantitative changes were seen in posterior cristae and cochlear sensory epithelia in the 1 x and 5 x SM injected groups, similar to those resulting from GM injections. Statistically significant decreases in number of hair cells were seen when 5 x SM injected ears were compared to 1 x SM injected ears and control ears. Increased damage was seen with increased dosage of each drug. Whenever damage was observed to the posterior crista sensory cells, damage was also seen in cochlear hair cells.

CONCLUSIONS

In this model, SM and GM produced significant cochlear damage when vestibular damage occurred. These results suggest that, in the gerbil, SM and GM are ototoxic but not selectively vestibulotoxic. Increasing the number of transtympanic injections generally increases the damage to sensory hair cells in the posterior crista and the cochlea. A variation in interanimal susceptibility to ototoxic effects exists, but the amount of damage is consistent in cochlear and vestibular hair cells from the same animal. No evidence for selective vestibular ototoxicity from transtympanic SM was found.

Study of the gerbil utricular macula following treatment with gentamicin, by use of bromodeoxyuridine and calmodulin immunohistochemical labelling

Effects of ototoxic drugs on the gerbil vestibular sensory epithelium were probed by use of immunocytochemical labelling with antibodies to both a mitogenic marker (bromodeoxyuridine) and a hair cell specific protein (calmodulin). Nine animals had gentamicin administered once daily for 5 days, as a transtympanic injection into the right middle ear. They additionally were given a daily intraperitoneal injection of bromodeoxyuridine, starting on the same day as the gentamicin injection and continuing until the day of sacrifice. Nine other animals, serving as controls for bromodeoxyuridine incorporation, received only the intraperitoneal injections of bromodeoxyuridine. The inner ears from three gerbils were obtained at 1, 2 or 4 weeks following the last gentamicin injection and utricles from the injected ears were processed for immunohistochemical analysis. In specimens where gentamicin was administered, we found evidence of bromodeoxyuridine incorporation in 17 cells (10 single cells and 7 pairs of cells) in a total of 216 sections taken from the central regions of the 9 utricles. However, in control specimens, no bromodeoxyuridine labelling was found in any cells of the 216 sections examined. Of 10 single cells labelled with bromodeoxyuridine, two cells in the hair cell layer were labelled with antibodies against calmodulin. One had a faint labelling in the nucleus and the other in the stereocilia, but not in the cell bodies. Of 7 pairs of cells, two pairs with nuclei localized in the hair cell layer had faint labelling for calmodulin in the nuclei, but no labelling in any other part of the cell. The other 13 cells labelled with antibodies to bromodeoxyuridine were not labelled with antibodies to calmodulin. Our results suggest that the bromodeoxyuridine-labelled cells could not be positively identified as hair cells based on immunohistochemical labelling for calmodulin.

Mechanism of DNA gyrase-mediated illegitimate recombination: characterization of Escherichia coli gyrA mutations that confer hyper-recombination phenotype

To study the mechanism of DNA gyrase-mediated illegitimate recombination in Escherichia coli, we isolated temperature-sensitive gyrA mutants that confer spontaneous illegitimate recombination and spontaneous induction of lambda prophage at higher frequencies than that in the wild-type. After reconstruction of single mutations by targeted mutagenesis, we confirmed that two single mutations, gyrAL492P and gyrAL488P, and a double mutation, gyrAI203V+gyrAI205V, show the same properties as those described above. With respect to the phenotypes of hyper-recombination and higher induction of lambda prophage, these mutations were dominant over the wild-type. Analysis of recombination junctions of lambdabio transducing phages formed spontaneously in these mutants showed that the parental E. coli bio and lambda recombination sites have a homologous sequence of only 0. 7 base-pair on average, indicating that homology is not required for this illegitimate recombination. Analysis of nucleotide sequences of mutant gyrA genes revealed that the gyrAL492P and gyrAL488P mutations contain amino acid substitutions of Leu492-->Pro and Leu488-->Pro, respectively, which correspond to the alpha18 helix in the breakage-reunion domain of DNA gyrase A subunit. The gyrAI203V and gyrAI205V mutations contain Ile203-->Val and Ile205-->Val, respectively, which correspond to the alpha10' helix, also in the breakage-reunion domain of DNA gyrase A subunit. Biochemical analysis indicated that the GyrA63 protein that contains the L492P mutation has an apparently normal supercoiling activity, but it also produces a small amount of linear DNA in the absence of DNA gyrase inhibitor during the supercoiling reaction, suggesting that the mutant DNA gyrase may have a defect at the step of religation or a defect in the subunit interaction. These results suggest that the recombination is induced by defects of religation and/or dimer formation in the mutant DNA gyrases, implying that two alpha helices, alpha10' and alpha18, of DNA gyrase A subunit have crucial roles in subunit interaction and/or resealing of DNA.

[Screening of prostate cancer with PSA and transperineal six sextant biopsy]

OBJECT

The objectives of this study are to examine how many cancer patients we can detect among the outpatients whose PSA values are above 4.0 ng/ml, and to compare the usefulness of transperineal six sextant biopsy (ss-biopsy) with that of transrectal one.

METHODS

All the male outpatients (above 50 years old) were inspected Tandem-R PSA levels and digital rectal examination (DRE). Among them, 129 patients showed more than 4.0 ng/ml of PSA values and/or positive finding of DRE, and underwent subsequent transperineal ss-biopsy.

RESULTS

Cancers were detected in 52 patients (40.3%) without major complications. Among 64 gray zone (PSA 4.1-10.0 ng/ml) patients, 17 (26.6%) were found to be cancer by ss-biopsy, meanwhile only 2 cancer patients (8.9%) were detected from 23 gray zone ones by traditional directed biopsy. Application of PSA density could not be found practicable to eliminate unnecessary biopsies in the gray zone group.

CONCLUSION

Prostate cancer could be found nearly a fourth in the gray zone group of the outpatients. To enhance the detection rate, obtaining at least 6 core samples are recommended from either perineal or rectal root.

Analysis of a catalytic pathway via a covalent adduct of D52E hen egg white mutant lysozyme by further mutation

We previously demonstrated by X-ray crystallography and electrospray mass spectrometry that D52E mutant hen lysozyme formed a covalent enzyme-substrate adduct on reaction with N-acetylglucosamine oligomer. This observation indicates that D52E lysozyme may acquire a catalytic pathway via a covalent adduct. To explain this pathway, the formation and hydrolysis reactions of the covalent adduct were investigated. Kinetic analysis indicated that the hydrolysis step was the rate-limiting step, 60-fold slower than the formation reaction. In the formation reaction, the pH dependence was bell-shaped, which was plausibly explained by the functions of the two catalytic pKas of Glu35 and Glu52. On the other hand, the pH dependence in the hydrolysis was sigmoidal with a transition at pH 4. 5, which was identical with the experimentally determined pKa of Glu35 in the covalent adduct, indicating that Glu35 functions as a general base to hydrolyze the adduct. To improve the turnover rate of D52E lysozyme, the mutation of N46D was designed and introduced to D52E lysozyme. This mutation reduced the activation energy in the hydrolysis reaction of the covalent adduct by 1.8 kcal/mol at pH 5.0 and 40 degrees C but did not affect the formation reaction. Our data may provide a useful approach to understanding the precise mechanism of the function of natural glycosidases, which catalyze via a covalent adduct.

A novel role of IL-15 in the development of osteoclasts: inability to replace its activity with IL-2

IL-15 shares many activities with IL-2 on stimulating lymphocytes, hematopoietic progenitor cells, and macrophages. However, the role of IL-15 in osteoclastogenesis has not been elucidated. The recent finding of abundant IL-15 in rheumatoid arthritis synovial fluids suggested a possible role for this cytokine in the pathological destruction of bone and prompted us to determine whether IL-15 stimulates osteoclast formation. IL-15 stimulated the formation of multinucleated osteoclast-like cells in rat bone marrow cultures. In stroma-free cultures, IL-15 increased the number of mononuclear preosteoclast-like cells in the early stage of osteoclast formation. The stimulation was observed even after treatment with IL-15 for only 24 or 48 h of culture. Moreover, low IL-15 concentration (0.1 ng/ml) strongly increased the level of calcitonin receptor mRNA of mononuclear preosteoclast-like cells. Although IL-15 is known as a potent stimulator of TNF-alpha, its activity was not abolished by addition of anti-TNF-alpha Ab. Interestingly, IL-2 and IL-7, which utilize some IL-15R components, had no effect on osteoclast differentiation, but pretreatment with IL-2 or IL-7 of bone marrow cells before the addition of IL-15 inhibited the enhancing activity of IL-15. In summary, IL-15 has a novel activity to stimulate the differentiation of osteoclast progenitors into preosteoclasts, which cannot be replaced by IL-2 but may use components in common with IL-2R to mediate its effects.

Detection of activated eosinophils in nasal polyps of an aspirin-induced asthma patient

Aspirin-induced asthma (AIA) is frequently accompanied by nasal polyps. Eosinophil infiltration is a characteristic feature of nasal polyps associated with AIA. Even though steroids are well known to be effective on managing AIA and its nasal polyps, histochemical examinations after steroid therapy and at recurrence, involving eosinophil infiltration of nasal polyps, have been less studied. To know the histochemical effects of steroid treatment on eosinophil accumulation in nasal polyps of AIA and the histochemical feature of a recurring polyp and to detect distributional differences between storage and secreted forms of eosinophil cationic proteins, we carried out immunocytochemical labelling with antibodies against EGI (recognizing resting and activated eosinophils) and EG2 (recognizing only activated eosinophils), and determined eosinophil infiltration in nasal polyps that were obtained before and after steroid treatment, and at recurrence of polyps. A large number of eosinophils in AIA polyps were found before steroid treatment and at recurrence, and they were predominantly composed of activated eosinophils (EG2-positive). In contrast, eosinophil infiltration was rare in polyps obtained immediately after steroid treatment. This finding suggests that eosinophil infiltration may be associated with nasal polyp formation in AIA, and that activation of eosinophils plays an important role in accumulation of eosinophils and polyp formation beginning with the initial stage.