[Vesico-acetabular fistula occurring 10 years after total hip replacement]

An 85-year-old female, who had had a total hip replacement for osteoarthritis in 1985, presented with gross hematuria in June 1995. Cystoscopy revealed a non-papillary sessile tumor in the right side wall of the urinary bladder with a crateriform opening on the top. Computed tomographic (CT) scan and excretory urography demonstrated a fistulous communication between the bladder and the acetabular bed filled with cement. The biopsy of the mass lesion suggested inflammatory granuloma with powdered cement. Since the lesion was composed of internal fistula, and was not accompanied with infection, the patient was treated conservatively. No external fistula had formed during the 5 months of observation.

Prognostic significance of Lens culinaris agglutinin A-reactive alpha-fetoprotein in small hepatocellular carcinomas

BACKGROUND & AIMS

Lens culinaris agglutinin A-reactive fraction of alpha-fetoprotein (AFP-L3) has been reported to be a useful marker in the early diagnosis of hepatocellular carcinoma (HCC). The aim of this study was to evaluate the prognostic value of AFP-L3 for HCC.

METHODS

Fifty-five patients with HCC whose AFP-L3 levels were negative before initial therapy were studied. AFP-L3 levels were measured by lectin-affinity electrophoresis coupled with antibody-affinity blotting.

RESULTS

Of the 55 patients, 28, 15, and 12 underwent percutaneous ethanol injection, transcatheter arterial embolization, and hepatectomy, respectively. Thirty-two (58.2%) of the 55 patients maintained a negative AFP-L3 status during the study, and 23 patients (41.8%) became positive for AFP-L3 during posttreatment observation. Multiple recurrences of HCC and portal vein tumor thrombus were observed significantly more often in patients with positive AFP-L3 than in those with negative AFP-L3 status (P < 0.0001). In contrast, most patients with negative AFP-L3 had solitary recurrences of HCC without portal vein tumor thrombus. Overall survival was significantly lower in patients with positive AFP-L3 than in those with negative AFP-L3 status (P = 0.0006). Cox's proportional hazards model identified that AFP-L3 was an independent prognostic factor (P = 0.0005).

CONCLUSIONS

AFP-L3 seems to be a significant marker of poor prognosis for HCC.

Effect of anticomplement agent K76 COOH on hamster-to-rat and guinea pig-to-rat heart xenotransplantation

In normal rats, the xenobiotic K76 inhibited the C5 and probably the C2 and C3 steps of complement and effectively depressed classical complement pathway activity, alternative complement pathway activity, and the C3 complement component during and well beyond the drug's 3-hr half-life. It was tested alone and with intramuscular tacrolimus (TAC) and/or intragastric cyclophosphamide (CP) in rat recipients of heterotopic hearts from guinea pig (discordant) and hamster (concordant) donors. Single prevascularization doses of 100 and 200 mg/kg increased the median survival time of guinea pig hearts from 0.17 hr in untreated controls to 1.7 hr and 10.2 hr, respectively; with repeated injections of the 200-mg dose every 9-12 hr, graft survival time was increased to 18.1 hr. Pretreatment of guinea pig heart recipients for 10 days with TAC and CP, with or without perioperative splenectomy or infusion of donor bone marrow, further increased median graft survival time to 24 hr. Among the guinea pig recipients, the majority of treated animals died with a beating heart from respiratory failure that was ascribed to anaphylatoxins. Hamster heart survival also was increased with monotherapy using 200 mg/kg b.i.d. i.v. K76 (limited by protocol to 6 days), but only from 3 to 4 days. Survival was prolonged to 7 days with the addition of K76 of intragastric CP at 5 mg/kg per day begun 1 day before operation (to a limit of 9 days); it was prolonged to 4.5 days with the addition of intramuscular TAC at 2 mg/kg per day beginning on the day of transplantation and continued indefinitely. In contrast to the limited efficacy of the single drugs, or any two drugs in combination, the three drugs together (K76, CP, and TAC) in the same dose schedules increased median graft survival time to 61 days. Antihamster antibodies rapidly increased during the first 5 days after transplantation, and plateaued at an abnormal level in animals with long graft survival times without immediate humoral rejection. However, rejection could not be reliably prevented, and was present even in most of the xenografts recovered from most of the animals dying (usually from infection) with a beating heart. Thus, although effective complement inhibition with K76 was achieved in both guinea pig- and hamster-to-rat heart transplant models, the results suggest that effective interruption of the complement cascade will have a limited role, if any, in the induction of xenograft acceptance.

Age-related extensive fragmentation of mitochondrial DNA into minicircles

In normal human hearts, a progressive age-related fragmentation of mitochondrial (mt) DNA into various-sized deleted (delta) mtDNA up to 358 types was documented by a novel total-detection system for deletions. The delta mtDNA lacking replication origin(s), minicircles, accumulated up to 280 types out of the 358, suggesting a yet unknown replication mechanism in human. Wild-type mtDNA decreased linearly down to 11% of the total with age negatively correlated with delta mtDNA and oxidized nucleoside, 8-hydroxydeoxyguanosine. A remarkable mirror image observed in delta mtDNA size distribution as well implies that random hydroxyl-radical attacks resulted in double-strand break and rejoining of mtDNA as a preferable mechanism to form various delta mtDNA of closed circular duplex. These facts support the 'redox mechanism of aging.'

Specific detection of deleted mitochondrial DNA by in situ hybridization using a chimera probe

We report a new method for the specific detection of the mutant mitochondrial DNA (mtDNA) that contains the 4977-bp deletion. We designed an oligonucleotide probe that was designated the 'ATP8/ND5 Chimera' probe: its 5'- and 3'-portions correspond to the ATP8 gene and the ND5 gene, respectively, and its middle portion includes the 13-bp direct repeat sequence that flanks the 4977-bp deletion. By Southern blot analysis, this chimeric probe specifically detected the deleted mtDNA, even in the presence of both normal mtDNA and other mtDNA deletions. The specificity of the probe was further confirmed by in situ hybridization of muscle fibers from patients with Kearns-Sayer syndrome who carry the deleted DNA in the heteroplasmic state. The deleted mtDNA was markedly accumulated in cytochrome-c oxidase (COX)-deficient ragged-red fibers. In tissues where multiple deleted mtDNAs were detected, such as muscle tissues from a patient with myotonic dystrophy and from an aged individual, the in situ hybridization detected a small number of muscle fibers that contained the deleted mtDNA. These results indicate that in situ hybridization using this chimera probe is a useful and specific method for detecting a small amount of deleted mtDNA.

Expression of structure-specific recognition protein mRNA in fetal kidney and Fe-nitrilotriacetate-induced renal carcinoma in the rat

Specific expression of the structure-specific recognition protein (SSRP) gene was investigated in rat fetal, adult, and tumor tissues using a 2.0-kb partial sequence of rat SSRP cDNA isolated from a cDNA library of rat renal cell carcinoma. The results revealed that it was rather specifically expressed in rat fetal kidney and renal cell carcinoma induced by Fenitrilotriacetate, but not in adult kidney, when various organs were tested by Northern blot analysis. In situ hybridization further demonstrated that it was located in the neoplastic cells of renal cell carcinoma and in the epithelial cells of fetal kidney but undetectable in any cells of normal adult kidney. These observations seem to imply the involvement of SSRP gene, which is believed to recognize structural alterations of DNA, in kidney development and carcinogenesis of certain types of kidney cancer.

Somatostatin neurons form a distinct peptidergic neuronal group in the rat suprachiasmatic nucleus: a double labeling in situ hybridization study

Accumulating evidence indicates that somatostatin (SS) is a key substance for the circadian rhythm of rodents. In the present study, we investigated whether SS mRNA coexists with arginine-vasopressin (AVP) mRNA, vasoactive intestinal peptide/peptide histidine isoleucine amide (VIP/PHI) mRNA and glutamate decarboxylase (GAD) mRNA in neurons of the rat suprachiasmatic nucleus (SCN) by double labeling in situ hybridization technique. SS mRNA-positive neurons were scattered in the whole region of rostral SCN, in the intermediate region between dorsomedial and ventrolateral region at the middle level, and in the mid to lateral region at the caudal level. These neurons were located in the close vicinities of the dorsomedial AVP and ventrolateral VIP/PHI mRNA-positive cell clusters. They rarely coexpressed AVP mRNA or VIP/PHI mRNA, but mostly coexpressed GAD mRNA. Thus, SS-synthesizing neurons are GABAergic and form a distinct cell group different from AVP or VIP/PHI cell groups.

[Three-dimensional-CT pancreatography under balloon-ERP in the pancreatic diseases--its method and usefulness]

Three-dimensional-CT pancreatography (3D-CTP) under balloon-ERP was carried out in 13 patients with the pancreatic diseases. Tapering stenosis of pancreatic duct in 2 patients out of 2 with pancreatic cancer, shape of cyst and relationship between cyst and pancreatic duct in 7 patients out of 7 with pancreatic cysts, and irregularity of wall of pancreatic duct in 2 patients out of 3 with chronic pancreatitis was reconstructed by 3D-CTP, stereographically. Moreover, the confluence of cyst and pancreatic duct in 3 out of 7 pancreatic cysts did not become clear on balloon-ERP, but it was distinct on 3D-CTP. It is suggested that 3D-CTP is useful in understanding pancreatic diseases stereographically, and can be applied to operative simulation, interventional radiology and differential diagnosis on them.

Gallbladder carcinoma in the era of laparoscopic cholecystectomy

OBJECTIVE

To assess the usefulness of laparoscopic cholecystectomy for unsuspected and suspected gallbladder carcinoma.

DESIGN

Retrospective review with a mean follow-up of 27 months, ranging from 1 to 47 months.

SETTING

University hospital and 8 affiliated hospitals.

PATIENTS

Of 2616 laparoscopic cholecystectomies performed over 4 years, 24 gallbladder carcinomas were treated by laparoscopic cholecystectomy and retrospectively reviewed.

RESULTS

The clinical course depended on the histopathologic depth of invasion of gallbladder carcinoma. All 6 cases of pathologic tumor (pT) stage in situ (pTis) gallbladder carcinoma and 2 cases of pT1 gallbladder carcinoma showed no invasion to the lymphatic, venous, or perineural spaces, and these 8 patients were all doing well from 2 to 19 months (mean, 11 months) after laparoscopic cholecystectomy. Sixteen cases of pT2 or pT3 gallbladder carcinoma invaded the subserosal layer or the liver, and 5 of the 16 patients were dead of liver dysfunction, abdominal wound recurrence, or liver metastasis 5 days and 7, 12, 15, and 18 months after operation, although additional resection of the liver bed with lymph node dissection was performed after laparoscopic cholecystectomy in 4 of these 5 patients. Abdominal wall recurrence in the absence of distant metastasis was present in 3 (19%) of the 16 patients with pT2 or pT3 gallbladder carcinoma due to inoculation of cancer cells in the abdominal stab wounds where the gallbladder or laparoscope was removed.

CONCLUSIONS

Gallbladder carcinoma at the pTis or pT1 stage removed laparoscopically needs no other treatment. We recommend that the gallbladder be removed by vinyl bag and port sites be excised or washed with normal saline to prevent port site recurrence in patients with laparoscopic cholecystectomy for pT2 or pT3 carcinoma.

[Study of hepatic arterial chemoinfusion with continuous CDDP, 5-FU low dose administration for advanced gallbladder cancer]

Eight unresectable cases of gallbladder cancer underwent hepatic-artery infusion (HAI) with a consequent combination of cisplatin (CDDP) and 5-fluorouracil (5-FU) administration at a continuous low dose. Five cases (62.5%) showed a partial response (PR). Median survival time was 481.9 days. Cytoreductive surgery was performed in three patients of PR. One case has been disease free and alive over 52 months postoperatively. Gallbladder cancer is well known as a chemoresistant cancer, whereas the higher response rate and the longer survival were achieved with HAI. These results suggested CDDP, 5-FU HAI is a useful chemotherapy for advanced gallbladder cancer, and it is also worthwhile to introduce the preoperative down-staging for consequent cytoreduction surgery.

Normovolaemic haemodilution attenuates cardiac depression induced by sodium bicarbonate in canine metabolic acidosis

This study was designed to determine if coexisting metabolic acidosis or normovolaemic haemodilution, or both, modifies the acute cardiodepressant effect of i.v. sodium bicarbonate. Thirty-one mongrel dogs were anaesthetized with halothane, and the lungs ventilated mechanically; dogs were allocated randomly to one of four groups: control group (pHa 7.39 (SD 0.03), base excess -1.0 (1.6) mmol litre-1, haemoglobin 13.9 (2.5) g dl-1 (n = 8)), metabolic acidosis group (pHa 7.21 (0.05), base excess -11.2 (2.1) mmol litre1, haemoglobin 13.4 (2.6) g dl-1 (n = 8)), anaemia group (pHa 7.40 (0.04), base excess 0.1 (2.0) mmol litre-1, haemoglobin 7.2 (1.1) g dl-1 (n = 8)) or anaemia acidosis group (pHa 7.22 (0.04), base excess -11.0 (2.2) mmol litre-1, haemoglobin 7.4 (0.3) g dl-1 (n = 7)). Metabolic acidosis was induced by continuous i.v. infusion of hydrochloric acid 2 mol litre-1. Normovolaemic haemodilution was undertaken by phlebotomy and simultaneous exchange with lactated Ringer's solution at 37 degrees C. Mean arterial pressure (MAP), pulmonary artery pressure, right atrial pressure (RAP), maximum rate of change of pressure in the right ventricle (RV dP/dtmax) and pulmonary blood flow (PBF) were measured at 30 s, 1 and 3 min after administration of 7% sodium bicarbonate solution 1 mmol kg-1 given into the right atrium over 5 s. Sodium bicarbonate produced significant decreases in MAP and RV dP/dtmax at 30 s in all groups except for the anaemia acidosis group (P < 0.05). There was a significant decrease in right ventricular stroke volume in the metabolic acidosis group from baseline values (P < 0.05), and compared with the three other groups (P < 0.05). These results indicate that the cardiodepressant effect of sodium bicarbonate 1 mmol kg-1 i.v. during metabolic acidosis was more pronounced than without acidosis, but was attenuated in the presence of normovolaemic haemodilution.

Granulomatous mastitis diagnosed and followed up by fine-needle aspiration cytology, and successfully treated by corticosteroid therapy: report of a case

A 36-year-old woman presented to our hospital with a rapidly growing lump in her left breast. Fine-needle aspiration (FNA) cytology of the mass revealed many epithelioid cells admixed with multinucleated Langhans-type giant cells, neutrophils, lymphocytes, and stromal cells, leading to a diagnosis of granulomatous mastitis. This report describes the clinical course of this patient in whom granulomatous mastitis was successfully treated with corticosteroid therapy. Special reference is made to the usefulness of FNA cytology in the diagnosis and follow-up of this disease.

Seasonality of mortality in Sri Lanka: biometeorological considerations

The seasonal variation of mortality in Sri Lanka was studied in relation to meteorological variables. Time series data of the total monthly number of deaths in men and women from 1976 to 1980 were analyzed by power spectrum analysis of the fast Fourier transformation method in the areas of Colombo (lowland area, altitude 7 m) and Nuwara-Eliya (highland area, altitude 1890 m), respectively. In the Colombo area, where the mean temperature was always high (mean, 27.5 degrees C), a seasonal variation in mortality of 6 months was validated by power spectrum analysis with peak times in June and November. These mortality peaks corresponded to those of the amounts of rainfall which also showed an identical predominant period of 6 months. In the Nuwara Eliya area, where the mean temperature was always low at about 15-16 degrees C, a seasonal variation of approximately 3 months was found in addition to the 6 months' periodicity. The comparison of the power spectrum pattern of mortality with those of meteorological variables suggested that the amount of rainfall was associated with the seasonal variation of mortality in the Nuwara-Eliya area. In conclusion, the seasonality of mortality in Sri Lanka, a typical tropical zone country, was related to seasonal variation in the amount of rainfall, or a humidity factor, but not to mean temperature.

Evidence that brain capillary endothelial cells can be infected with murine leukaemia retrovirus, LP-BM5

Some mice infected with murine leukaemia retrovirus, LP-BM5 including ecotropic, mink cell focus-inducing murine leukaemia virus, and a replication-defective genome, have been reported to show weakness, ataxia, or selective deficits in spatial learning after developing an immunodeficiency syndrome similar to human AIDS. In the central nervous system, astrocytes and microglial cells have been shown to be infected by this virus. We present here findings that the ecotropic virus and defective genome can infect murine brain capillary endothelial cells, and infected endothelial cells show an impaired function as target cells against myelin basic protein (MBP) specific T cell clone.

Solubilization and characterization of binding sites for [3H]NE-100, a novel and potent sigma 1 ligand, from guinea pig brain

The binding sites for [3H]NE-100, a newly defined sigma 1 ligand, was solubilized from guinea pig brain, using zwitterionic detergent 3-[(3-c holamidopropyl) dimethylamino]-1-propanesulfonate (CHAPS), and the properties of the solubilized binding sites were compared to those for [3H](+)-pentazocine, a selective sigma 1 ligand. The pharmacological selectivity of solubilized sites for both [3H]NE-100 and [3H](+)-pentazocine was identical to that obtained from membrane preparations. Stereoselectivity of benzomorphan such as pentazocine and SKF10,047 was preserved in displacing [3H]NE-100 binding in solubilized preparations as observed in membrane preparations. The inhibitory potencies of several sigma ligands on [3H]NE-100 binding were similar to those on [3H](+)-pentazocine binding, indicating that the pharmacological characteristics of the binding sites for [3H]NE-100 are retained after solubilization. Phenytoin augmented the binding of [3H](+)-3-(3-hydroxyphenyl)-N-(1-propyl) piperidine hydrochloride (3-PPP) to solubilized sigma binding sites while it had no effect on the binding of [3H]NE-100. Furthermore, the inhibitory effect of putative sigma receptor agonists such as (+)-3-PPP and dextromethorphan were enhanced by phenytoin; the effects of haloperidol, a putative sigma receptor antagonist, were unaltered. Molecular weight of [3H]NE-100 binding protein was estimated to be 440KDa by Sepharose CL-6B gel filtration chromatography, and the value was identical to that of [3H](+)-pentazocine binding protein, a putative sigma 1 binding protein. These findings indicate that [3H]NE-100 binding sites are putative sigma 1 binding sites, and that NE-100 may act as an antagonist at sigma 1 binding sites.

Bile acid synthesis and biliary hydrophobicity during obstructive jaundice in rats

Hepatic cholesterol 7alpha-hydroxylase, the rate-limiting enzyme for bile acid synthesis, is regulated by bile acid returning to the liver. In the bile duct-ligated rats, however, cholesterol 7alpha-hydroxylase activity is known to increase in spite of the elevated serum bile acids. The aim of this study was to investigate the relationship between the bile acid synthesis and biliary hydrophobicity to solve the paradoxical phenomenon. Male Wister rats (250-350 g) were divided into two groups, bile duct-ligated group and sham-operated group. Rats were sacrificed on the Days 1, 2, 4, 7, and 14 after the operation. Cholesterol 7alpha-hydroxylase activity, biliary bile acid composition, and biliary hydrophobicity were analyzed. Hepatic and serum total bile acid concentrations and serum 7alpha-hydroxycholesterol levels were also determined. Bile duct ligation caused significant increases in hepatic and serum bile acid concentrations on Day 1, which persisted for 14 days after the bile duct ligation. Activities of hepatic cholesterol 7alpha-hydroxylase increased to 3.2-fold of the preoperative value on Day 2, remained significantly high until Day 7, and then decreased to the basal value on Day 14. The serum 7alpha-hydroxycholesterol level essentially behaved in a similar fashion to that of hepatic cholesterol 7alpha-hydroxylase activity with a significant (P < 0.01) positive correlation. beta-Muricholic acid was predominant in bile until Day 7 (71 vs 10% in the controls on Day 4; P < 0.05) with a concomitant decrease in the proportion of cholic acid. Biliary bile acid became less hydrophobic and hepatic cholesterol 7alpha-hydroxylase activity significantly correlated with the hydrophobicity of biliary bile acids (n = 55, r = 0.54, P < 0.01). There were no significant correlations between the activity of cholesterol 7alpha-hydroxylase and total bile acid concentrations in serum, liver, or bile. The increased cholesterol 7alpha-hydroxylase activity is accompanied by the decreased biliary hydrophobicity, which may be a rationale for the paradoxical increase in bile acid synthesis in spite of the accumulation of bile acids in the serum and liver during obstructive jaundice in rats.

Synthesis and antitumor activity of 1-[2-(chloroethyl)-3-(2-substituted-10H-phenothiazin-10-yl)alkyl- 1-urea s as potent anticancer agents

10-[N-(Phthalimido)alkyl]-2-substituted-10H-phenothiazines and 1-(2-chloroethyl)-3-(2-substituted-10H-phenothiazin-10-yl)alkyl-1- ureas were synthesized and found to have antiproliferative effects on human HEp-2 and L5178Y cell cultures. The multi-drug resistant subline of mouse lymphoma was sensitive to the reversal effects of some 10-[N-(phthalimido)alkyl]-2-substituted-10H-phenothiazines, while 1-(2-chloro-ethyl)-3-(2-substituted-10H-phenothiazin-10-yl)alkyl-1 -ureas were less effective but had a similar degree of antiproliferative effect on both cell lines.

Diverse mutagenicity of methylbenz[c]acridines in the direct Ames' Salmonella mutagenicity assay

The mutagenicity of eleven methylbenz[c]acridines (methyl-B[c]ACRs) was examined by the direct Ames' Salmonella mutagenicity assay on the standard tester strains of TA97a, TA98, TA100 and TA102, each of which is specific to a certain type of mutation. The Benz[c]acridines (B[c]ACRs) studied in this investigation were substituted with one to three methyl group(s) at the 5, 7, 8, 9, 10 and 11 position(s) of B[c]ACR. A certain degree of mutagenic activity was observed by all methyl-B[c]ACRs on at least one of the tester strains, indicating that even non-carcinogenic methyl-B[c]ACRs showed mutagenicity in the assay. Meanwhile, 7,10-dimethyl-B[c]ACR and 7,9,10-trimethyl-B[c]ACR significantly increased the number of back-mutant colonies. However, monomethyl-B[c]ACRs, 7-methyl-B[c]ACR and 10-methyl-B[c]ACR did not increase back-mutation except for TA102 and TA100, respectively. The induction of 7-methyl substituent on B[c]ACR appears to play a key role in frameshift (+1 and -1), base-pair substitution, and single base substitution mutation of the strains in the presence of additional methyl substituent(s) at C-9 and/or C-10 position(s) of D ring of B[c]ACR.

ASA physical status and age are not factors predicting morbidity, mortality, and survival after pancreatoduodenectomy

To evaluate the effects of age and physical status on postoperative complications, American Society of Anesthesiologists-Physical Status score (ASA score) and age were analyzed in patients undergoing pancreatoduodenectomy (PD). Medical records and follow-up results of 69 patients who had undergone PD from 1980 to 1993 at one institution were examined. Clinical variables affecting morbidity and mortality rates were analyzed, and compared between two-aged groups (> or = 70 years (n = 18) and < 70 (n = 51)). Univariate Cox regression analysis of 69 patients showed that ASA score and age were not significant factors affecting postoperative morbidity, mortality, and survival. The clinical variables including ASA score, gender, operative time, blood loss, stage, and location of carcinoma were similarly distributed between the two-aged groups. The mortality rate in patients less than 70 years of age was 5.9 per cent (3/51), whereas there was no mortality in patients more than 70 years of age. The morbidity, mortality, and cumulative survival rates were statistically similar in the two age groups. The results suggest that ASA-physical status and age are not limiting factors for PD and do not predict survival. The procedure is safe and worthwhile even in patients more than 70 years of age with the ASA score up to III.

Serum interleukin-6 levels after urologic operations

BACKGROUND

Endourology, extracorporeal shock wave lithotripsy (ESWL), and laparoscopic surgery are considered minimally invasive procedures; however, estimation of operative invasiveness has not been fully accomplished. We measured serum interleukin-6 (IL-6) levels, as an indicator for systemic reaction, to examine operative invasiveness of these operations in comparison with open surgery.

METHOD

Serum IL-6 levels were measured in 119 patients undergoing open surgery, laparoscopic surgery, endourology, and ESWL.

RESULTS

The median IL-6 levels on day 1 after the operation varied according to operative procedures: 83.5 pg/mL (range, 15-340 pg/mL) for open surgery, 24.8 pg/mL (range, 12-42 pg/mL) for laparoscopic surgery, and 10.8 pg/mL (range, 0-85 pg/mL) for endourology and ESWL. The extent of tissue injury and blood loss were found to be 2 major factors responsible for the serum IL-6 elevation.

CONCLUSION

The minimally invasive character of endourology, ESWL, and laparoscopic surgery is attributable to low levels of tissue injury and blood loss, regardless of operative time.

Analysis of M phase-specific phosphorylation of DNA topoisomerase II

In mammalian cells, two isoforms of DNA topoisomerase II (topo II), topo IIalpha and topo IIbeta, are phosphorylated. The phosphorylation of topo IIbeta changes its apparent molecular mass determined by SDS-polyacrylamide gel electrophoresis from 180 to 190 kDa in mitotic cells, whereas topo IIalpha affects it only slightly (Kimura, K., Nozaki, N., Saijo, M., Kikuchi, A., Ui, M., and Enomoto, T. (1994) J. Biol. Chem. 269, 24523-24526). Here we examined the stability of the protein and the phosphate moiety of each topo II isoform, as the cells progressed from M to G1 phase. While its protein moiety remained intact, 75% of the phosphates attached to topo IIbeta were removed within 4 h after release from mitotic block. On the other hand, 35% of topo IIalpha protein and 52% of the attached phosphates disappeared. We verified that M phase-specific phosphorylation had no particular effect on the catalytic activities of both topo II isoforms after extensive phosphatase digestion. We also examined the binding of two isoforms to the nucleus or chromosomes. In logarithmically growing cells, both isoforms were extracted from nuclei at the same concentrations of NaCl. From the mitotic chromosomes, topo IIbeta was extracted at much lower concentrations of NaCl than topo IIalpha.

Orally active, nonpeptide vasopressin V2 receptor antagonists: a novel series of 1-[4-(benzoylamino)benzoyl]-2,3,4,5-tetrahydro-1H-benzazepines and related compounds

This paper describes a novel series of nonpeptide vasopressin V2 receptor antagonists. It has been demonstrated that the 1-[4-(benzoylamino)benzoyl]-2,3,4,5-1H-benzazepines and 1-[4-(benzoylamino)benzoyl]-2,3,4,5-1H-1,5-benzodiazepines show a high affinity for V2 (and V1a) receptors. Among the 1-[4-(benzoylamino)benzoyl]-2,3,4,5-1H-benzazepine series, compounds with an alkylamino group on the benzazepine ring have been shown to have oral activity. A lipophilic group at the ortho position on the terminal benzoyl ring is important for both high V2 receptor affinity and oral activity. On the basis of these favorable properties, clinical testing of 31b has begun for use as an oral and iv aquaretic agent.

Representation of reaching and grasping in the monkey postcentral gyrus

In area 2 and further caudal part of the alert monkey's postcentral gyrus, we found neurons which were activated preferentially or only by monkey's self-initiated hand actions to reach or grasp objects. Among them we studied those neurons which were selective to either (1) projecting the arm and stretching digits toward an object (reaching); (2) grasping with the first and the second digit (radial grasp, precision grip); (3) grasping with the ulnar digits and palmar skin (ulnar grasp, whole hand grip); or (4) scratching or touching an object with distal digit pads and nails. Neurons of the radial grasp type were found in the lateral part of the digit region while all other types of neurons were found in the medial part. Each of hand action neurons was found in a cluster of neurons which had common receptive fields corresponding to effective sites for the particular type of grasping.

Calcium-dependent potentiation of M-current in bullfrog sympathetic neurons

Whole-cell voltage-clamp recordings were made from cultured bullfrog sympathetic neurons to measure the steady-state activation curve of M-type potassium current. When measured with a calcium-deficient (10 nM) pipette solution M-conductance was 4.8 nS at -35 mV having the 50%-activation voltage at-20 mV. Respective values were 17.2 nS at -35 mV with the 50%-activation voltage at -42 mV when measured with a calcium-rich (1 microM) solution, indicating the hyperpolarizing displacement of the activation curve with high internal calcium. It is suggested that intracellular calcium ions can modulate kinetics of M-current which thereby regulate the number of M-channels being open at given membrane potentials.

Preliminary examination of the influence of incubation time or cytosolic protein concentration on dihydropyrimidine dehydrogenase activity

We examined the influence of incubation time or cytosolic protein concentration on the metabolite production of 5-fluorouracil (5FU). Although the activity of dihydropyrimidine dehydrogenase (DPDase) from rat liver is considered to be retained for up to 60 min, the production rate of 5FU metabolites was reduced, probably due to depletion of the substrate in 40 mumol/l and lower concentration of 5FU. Since the ratio of the metabolite production rate to the cytosolic protein became smaller in higher concentrations of cytosolic protein, the DPDase activity should be compared in the same concentration of cytosolic protein. The production rate of 5FU metabolites was considered to be linear up to 40 mumol/l 5FU incubated with 500 micrograms cytosolic protein. The rate of the metabolite production calculated by one-point sampling significantly correlated with the enzyme activity by the multi-point sampling method. Minimizing sampling points to determine the DPDase activity would save time and expense.