Biomedical subjects

K Maeno

Publications and source records attributed to K Maeno.

At least 37 records · Page 2Linked to original sources

PubMed1993

[DNA ploidy of testicular germ cell tumors in childhood; difference from adult testicular tumors].

It is well known that there are various differences in the biological characteristics and clinical behavior between prepubertal testicular germ cell tumors and adult ones. We analyzed the nuclear DNA ploidy of testicular tumors in childhood using DNA flow cytometry for clarifying those biological features and shedding some insights in the pathogenesis of testicular germ cell tumors. Formalin-fixed, paraffin-embedded specimens of primary tumors taken from 9 boys with histological evidence of yolk sac tumors and 8 with prepubertal teratoma treated in our clinic were used for flow cytometry analysis with some modification of the Hedley's technique. The results were compared with those of adult testicular tumors which we previously reported. All specimens in children showed "DNA euploid"; DNA diploid in all teratomas and 6 yolk sac tumors, DNA tetraploid in other 3 yolk sac tumors. Neither distinct DNA aneuploidy nor DNA heterogeneity were detected in children. Our previous study proved that the vast majority of adult testicular tumors contain DNA aneuploid stemlines. Although prepubertal yolk sac tumor and teratoma are histologically identical with those in adults, this study apparently reveal the different DNA stemline ploidy in prepubertal testicular tumors compared with that in adult ones. It has been known that carcinoma in situ (CIS) of the testis is a precursor of adult testicular germ cell tumors and the CIS cells in precancerous state already shows aneuploid DNA histogram patterns. Moreover, CIS has never been observed in children. The current results are in agreement with the hypothesis that the pathogenesis of prepubertal testicular tumor is different from that of adult ones.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

The pathogenicity of ribonucleotide reductase-null mutants of herpes simplex virus type 1 in mice.

The pathogenicity of ribonucleotide reductase (RR)-null mutants (hrR3 and ICP6 delta) of herpes simplex virus (HSV) type 1 was studied after intracerebral and corneal inoculation in newborn and adult ICR mice. ICP6 delta failed to replicate in brains of mice greater than or equal to 8 days old but exhibited significant virulence for newborn mice as a result of viral replication in the brains. The RR- and a thymidine kinase (TK)-deficient mutant of HSV-1 strain KOS could grow in eye tissues of adult ICR mice. Viral DNA of hrR3 was detected in brain tissues of intracerebrally infected mice or in the trigeminal ganglia of corneally infected mice greater than or equal to 50 days after infection, and infectious hrR3 could be recovered from these tissues by superinfection of the mice with wild-type HSV-2. These observations indicate that pathogenicity of RR- mutants in mice is highly dependent on the physiologic state of tissues infected and that RR- mutants have the ability to establish latency in nervous system tissues of mice by either the peripheral or intracerebral route. It was also demonstrated that the inability of the RR- mutants to invade the central nervous system was efficiently complemented by simultaneous infection with another defective virus, the TK- mutant of KOS.

Animals↗

PubMed1991

Role of viral ribonucleotide reductase in the increase of dTTP pool size in herpes simplex virus-infected Vero cells.

Infection of Vero cells with herpes simplex virus (HSV) causes a marked increase in the dTTP pool size of infected cells. In this study we examined the relative importance of the HSV-encoded ribonucleotide reductase (RR) and thymidine kinase (TK) in the increase of dTTP. In cells infected with an RR deletion mutant of HSV-1 strain KOS, there was no significant increase in the size of the dTTP pool, whereas the dTTP pool in HSV-1(TK-)-infected cells was increased in size to almost the same extent as that in HSV-1(TK+)-infected cells. Moreover, it was found that the increase in dTTP pool size was strongly inhibited by the addition of hydroxyurea, a specific inhibitor of RR, and 5-fluoro-2'-deoxyuridine, a specific inhibitor of thymidylate synthetase. These results suggest that the induction of viral RR is of primary importance in the increase of dTTP pool size in HSV-1-infected Vero cells.

Animals↗

PubMed1991

[Early experience with an ileocolic bladder substitution (Mainz pouch) in 11 cases].

In the last decade, many continent urinary diversions have been developed for the cystectomy patients. Mainz pouch, which seems to be a sophisticated one without using an alloplastic prosthesis, was adopted in our clinic. We preliminarily report our result in 11 patients who underwent a Mainz pouch procedure in the last 2 years: 1 for bladder augmentation, 5 for total bladder substitution after cystoprostatectomy and 5 (including 2 females) for continent urinary diversion. The mean age of them was 54 years old and the follow up periods ranged from 6 to 24 months. The antimesenteric longitudinal incision of the ileum and cecum and their sutures were performed similarly to the usual detubularized intestinal pouch. The ureteral reimplantation to the colonic segment was accomplished by the submucosal tunnel method. Although the ureteral hiatus was initially positioned at the anal edge of the colon, a new hiatal creation by stabbing the more oral portion of the colon according to the Goodwin's ureterocolic anastomosis was subsequently employed to avoid the trouble of closure of this portion. When the urethral anastomosis was achieved by 4-5 interrupted sutures between the most dependent portion of the cecum and the urethral stump after cystoprostatectomy, the mucosa was everted to the colonic serosa to prevent the stricture. The continent stoma was created by an intussusception of the proximal ileum, which was stabilized by the seromuscular stripping and 2-3 rows of external metal staples. Complication of the alimentary system occurred in 6 of 11 cases (55%), though they were successfully treated by an appropriate conservative management except one who suffered an ileostomy and nephrostomy because of severe panperitonitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

[Long-term follow up of transurethral resection of the prostate--a review of 137 patients].

For assessing the long-term outcome of patients after transurethral prostatic resection (TUR-P), telephone interview in terms of the urinary symptom and the sexual function was conducted on 191 cases who underwent TUR-P in Hokkaido University Hospital from 1982 to 1988. Adequate replies were obtained from 137 patients (71.7%), whose mean age was 70.2 years old and mean follow up period was 4.8 years. Subjective urinary symptoms, which are mainly classified as dysuria, frequency and incontinence, were improved in 114/120 (95.0%), 99/108 (91.7%), and 20/21 (95.2%) respectively. Overall symptom-free rates of dysuria, frequency, and incontinence were 85.1% (114/134), 86.6% (116/134), and 90.3% (121/134). Morbidity of incontinence following TUR-P was only 6/134 (4.5%). There was one deaths (0.7%) at 2 weeks after TUR-P, but was not attributable to the operative procedure itself. Although 82 cases (59.9%) had risk factors such as the cardiovascular disease, malignancy or other systemic disorders, they did not jeopardize the postoperative course nor were attributed to the mortality. Uninhibited contraction and/or vesical denervation supersensitivity on perioperative cystometrogram were found in 53/84 (63%). These urodynamic abnormalities were not considered to be postoperative urinary symptoms. Postoperatively, the decrease in libido was noted in 12/63 (19%), but its causal relation to the procedure was obscure in most of the patients. We believe TUR-P can offer a satisfactory outcome in the majority of the patients with minimum risk.

Aged↗

PubMed1990

Selective suppression of human papilloma virus type 18 mRNA level in HeLa cells by interferon.

We have studied the effect of IFN on the transcription of integrated HPV 18 DNA in HeLa cells. We found that the amount of cytoplasmic HPV 18 mRNA was markedly reduced in HeLa cells treated with 10(3) IU/ml of IFN alpha or gamma, and that the inhibitory effect was dose dependent and was detectable by 12h after the addition of IFN. Furthermore, northern blot analysis indicated that IFN remarkably reduced 3.4 kb mRNA species of HPV 18 transcripts in HeLa cells. In contrast, the level of beta-actin mRNA was found to increase in IFN treated cells. The results suggest that IFN alpha and gamma selectively inhibited HPV 18 gene expression at the level of transcription.

Cell Cycle↗

PubMed1990

Role of DNA topoisomerase I in the replication of herpes simplex virus type 2.

Camptothecin (CPT), a specific inhibitor of DNA topoisomerase I, effectively inhibited the replication of herpes simplex virus type 2 (HSV-2). CPT was found to reduce the level of immediate early viral mRNA in a dose-response manner. On the other hand, we could not find any evidence that a novel DNA topoisomerase I was induced in HSV-2-infected cells. Our observations suggest that host cell DNA topoisomerase I is involved in the replication of HSV-2.

Camptothecin↗

PubMed1990

[A case of candida endocarditis with consecutive measurement of serum mannan and D-arabinitol concentrations].

We encountered a case of an 83-year-old patient with candida endocarditis. He had been diagnosed as having aortic regurgitation with moderately calcified aortic valve 5 years previously, and had received medication. He was admitted to our hospital because of pancreatic cancer. He had high fever from the time of his admission and antibiotics produced no effect. Candida albicans was detected in arterial blood culture. We also detected antibody against Candida albicans, and investigated serum mannan and the D-arabinitol creatinine ratio several times. We performed echo-cardiographic examination and recorded a vegetation at the aortic valve. Rising antibody titers against Candida albicans, mannan antigenemia and an elevated creatinine ratio were also observed. So we concluded that these examinations were also effective in the diagnosis of candida infection. Finally, this patient died of cerebral hemorrhage and was autopsied. Macroscopic findings showed mass-like vegetation involving the aortic valve, and microscopic findings showed candida organisms scattered within the vegetation.

Aged↗

PubMed1989

Involvement of prostaglandin-induced proteins in the inhibition of herpes simplex virus replication.

Cyclopentenone prostaglandin (PG), delta7-PGA1 was found to induce several polypeptides in human embryonic fibroblast (HEF) cells which were noticed to be dose-related and appeared after 1 h of treatment with a peak at around 5 h and gradual disappearance after 12 h. PG-induced proteins were almost identical in terms of molecular weights with those induced by heat-shock at 42 degrees C. Regarding the mechanism of inhibition of herpes simplex virus (HSV) replication by PG in cell culture, dot blot hybridization has revealed that the level of immediate early (IE) mRNA of the virus was reduced after PG treatment with time dependence. And this delayed inhibitory effect of delta7-PGA1 on HSV was shown to be associated with the production and accumulation of the induced polypeptides.

Cells, Cultured↗

PubMed1989

Mannan and D-arabinitol concentrations in serum from a patient with Candida albicans endocarditis.

In an attempt to clarify the comparative values of serological and microbiological examinations for the early diagnosis of systemic candidiasis, antibodies against Candida albicans, serum mannan, and the D-arabinitol creatinine ratio were investigated in a patient with aortic valve endocarditis associated with carcinoma of the bile duct. Candida precipitins and the antibody titer against Candida cell wall mannan were examined by an immunodiffusion technique and hemagglutination test, respectively. Serum mannan was tested by enzyme-linked immunosorbent assay (ELISA) using the biotin-streptavidin procedure. The upper limit of negativity of the assay was determined by adding 0.06 to the absorbance of pooled serum from healthy laboratory workers. This value was about 0.8 ng/ml with ELISA. The D-arabinitol concentration in serum was examined by an enzymatic fluorometric method. Rising antibody titers against C. albicans, mannan antigenemia, and an elevated D-arabinitol creatinine ratio were first observed between the 11th and 12th hospital days. Blood cultures obtained on 8th, 9th, and 11th hospital days grew C. albicans after 3 to 4 days of incubation. Of 11 serum samples, 5 were positive for mannan, whereas D-arabinitol creatinine ratio was positive in 7 of 9 samples. Blood cultures was the earliest evidence of Candida infections in our cases. However, because of saprophytic nature of Candida species, tests for antibodies, antigenemia, and the D-arabinitol creatinine ratio in combination with blood cultures are necessary to confirm systemic candidiasis at an early stage of infection.

Adenocarcinoma↗

PubMed1989

Anti-herpesvirus activity of citrusinine-I, a new acridone alkaloid, and related compounds.

Citrusinine-I, a new acridone alkaloid isolated from the root bark of the citrus plant (Rutaceae), exhibited potent activity against herpes simplex virus (HSV) type 1 and type 2 at low concentrations relative to their cytotoxicity; 50% effective concentrations (ED50) of citrusinine-I were 0.56 micrograms/ml and 0.74 micrograms/ml against HSV-1 and HSV-2, respectively. Inhibitory action was also demonstrated against cytomegalovirus (CMV) and thymidine kinase-deficient or DNA polymerase mutants of HSV-2. The compound markedly suppressed HSV-2 and CMV DNA synthesis at concentrations which did not inhibit the synthesis of virus-induced early polypeptides. However, citrusinine-I had no inhibitory activity against HSV and CMV DNA polymerases in cell-free extracts. Although the target of this inhibitor remains to be elucidated, the most plausible candidate is a virus-coded ribonucleotide reductase. Citrusinine-1, when combined with acyclovir or ganciclovir, synergistically potentiated the antiherpetic activity of these agents. Based on a comparative study of the antiherpetic activity of citrusinine-1 and 28 related compounds, a structure-activity relationship could be established.

Acridines↗

PubMed1989

Persistent infection of MDCK cells by influenza C virus: initiation and characterization.

Persistent influenza C virus infection was readily initiated in Madin-Darby canine kidney (MDCK) cells at low m.o.i. and has been maintained for over 1 year. The persistently infected (p.i.) cultures were characterized by the following properties: virus infection was limited to a minority of cells, small amounts of infectious virus were produced together with low levels of interferon (IFN) and the cultures were resistant to superinfection by homologous virus and vesicular stomatitis virus, but not by influenza A and B viruses. These properties fluctuated cyclically with passage of the p.i. culture. When p.i. cultures were cured by cultivation in the presence of antiserum, the cultures lost their IFN-producing activity and became as susceptible to homologous virus as normal MDCK cell culture. The results suggest that persistent influenza C virus infection may be regulated by endogenously produced IFN. Under the condition of high m.o.i. a persistent influenza C virus infection could not be initiated in MDCK cells due to the development of cytopathic effects.

Animals↗

PubMed1989

Effects of atropine on adrenergic responsiveness and reflex vasoconstriction in humans.

To determine whether cholinergic mechanisms contribute to blood pressure regulation, we examined the effects of atropine on pressor responses to phenylephrine and vasoconstrictor responses to the cold pressor test (CPT) and lower body negative pressure (LBNP) in 16 healthy subjects. Heart rate, blood pressure and cardiac index were significantly increased, and central venous pressure (CVP) was significantly decreased after atropine (0.04mg/kg). After atropine, pressor responses to phenylephrine at doses of 20, 40 and 80 micrograms were significantly increased by 101, 112 and 93% (p less than 0.001); however, atropine attenuated pressor responses to CPT (p less than 0.001) and forearm vasoconstrictor responses to LBNP. In 6 propranolol-treated subjects, atropine also augmented pressor responses to phenylephrine but attenuated pressor responses to CPT. These results suggest that atropine augments the pressor response to an alpha-agonist, which may be partly explained by inhibition of compensatory vascular responses mediated by cholinergic mechanisms.

Adult↗

PubMed1989

[Progression of a new lesion after percutaneous transluminal coronary angioplasty--report of a case].

A-62-years-old man was admitted our hospital because of angina at rest and during effort. Coronary angiography revealed 25% fixed stenosis in Seg. 6, 90% in Seg. 7, 75% in Seg. 10, and 50% in Seg. 12. Percutaneous transluminal angioplasty was performed for segment 7 and complete revascularization was obtained finally. Two and a half months later, progressive lesion occurred in the segment proximal to the angioplasty site (Seg. 6). The manipulation of the guiding catheter in the coronary artery proximal to the PTCA site might have developed atherogenesis in this area. So we must consider the possibilities of both restenosis and new lesions when one has the recurrence of ischemic symptoms after coronary angioplasty.

Angina Pectoris↗

PubMed1989

[Effective hormone therapy of prostatic cancer with lung metastasis: 2 cases].

Many prostatic cancer patients have local symptoms such as dysuria and hematuria, but relatively few are seen with lung metastasis. This time we experienced 2 cases of prostatic cancer with a lung metastasis focus as the first symptom. Administration of diethylstilbestrol 500 mg/day for 20 days produced marked effects; reduction or disappearance of the lung metastasis focus, noticeable reduction of prostatic tumor and the improvement of their total condition. The literature is also reviewed.

Adenocarcinoma↗

PubMed1988

Analysis of the mechanism of influenza B virus inactivation by guinea pig serum.

Normal guinea pig serum lacking detectable antiviral antibody inactivated influenza B virus via the classical complement pathway. This virus inactivation appeared to result from the steric hindrance of HA activity by the association with the virus of serum proteins presumed to be complement components. Trypsin digestion of the associated proteins fully restored the HA activity but not infectivity. It was found that the virus underwent minor disruption of the envelope and degradation of M1 protein and genomic RNA.

Animals↗

PubMed1988

[Malignant fibrous histiocytoma of the scrotal wall--a case report].

The case involves a 64-year-old male who was found to have a gradually enlarging tumor which was responsible for a slight tenderness in his scrotum for a month. Tumor excision was performed, and the tumor size was found to be 3 X 2 X 2 cm. A histologic examination of this tumor revealed a malignant fibrous histiocytoma of the scrotal wall. The patient received UFT chemotherapy. Five months after the excision, the patient was rehospitalized with a local recurrence in the scrotum. After a second operation, the patient was treated with radiotherapy.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1987

Mechanism of inhibition of herpes simplex virus replication by delta 7-prostaglandin A1 and delta 12-prostaglandin J2.

We studied the effect of prostaglandins (PGs) A1, delta 7-A1, A2, D2, E1, E2, F2 alpha, J2 and delta 12-J2 on the replication of herpes simplex virus type 2 (HSV-2). Of nine PGs we tested, delta 7-PGA1 was found to have the most potent inhibitory effect; 50% inhibitory dose (ID50) was 0.35 microgram/ml in the plaque reduction assays and HSV-2 induced protein synthesis was strongly suppressed at 0.5 microgram/ml whereas at this dose, the protein synthesis of uninfected cells was not inhibited. Dot blot hybridization analysis revealed that delta 7-PGA1 and delta 12-PGJ2 inhibited the primary transcription of HSV-2. Thus we suggest that those PGs are primarily active at the level of mRNA synthesis.

Cell Transformation, Viral↗