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N Nagai

Publications and source records attributed to N Nagai.

At least 19 recordsLinked to original sources
PubMed1992

Effect of orbital enucleation on glucose homeostasis and morphology of the suprachiasmatic nucleus.

In rats there is a direct neural connection called the retinohypothalamic tract (RHT) from retinal ganglion cells to the ventrolateral part of the suprachiasmatic nucleus (SCN), which has neurons containing vasoactive intestinal polypeptide (VIP)-like substance. Previously, we observed that bilateral orbital enucleation (blinding) caused temporary suppression of the hyperglycemic response to intracranial injection of 2-deoxy-D-glucose (2DG) from week 4 to 6 after blinding. Moreover, bilateral lesions of the SCN had a similar effect. From these findings, we supposed that the neurons responsible for the hyperglycemic response to 2DG were present in the SCN, that after blinding these neurons temporarily lost their activity, and that this functional change was reflected in the morphology of the SCN. To investigate this possibility, we examined the morphological changes of the SCN by Nissl staining and immunohistochemical studies with anti-VIP and anti-peptide histidine isoleucine (PHI) antibodies in blinded rats, and the relationship between these morphological changes and the hyperglycemic response to 2DG. After surgical blinding, we observed following changes. (1) The optic chiasm became thinner. (2) The SCN became displaced rostrally. (3) The density of neurons in the middle to caudal part of the SCN, where the retinal ganglion cells projected, decreased markedly without change in cell number during the period when the hyperglycemic response to intracranial injection of 2DG was temporarily suppressed after blinding. The first and second changes seemed to reflect reduction of fibers and axon terminals of retinal ganglion cells and their innervation, respectively. As the third change was parallel with suppression of the hyperglycemic response to 2DG injection, it may reflect functional change of the neurons in the SCN that are responsible for the hyperglycemia due to 2DG.

Animals↗
PubMed1992

Light enhances sympathetic and suppresses vagal outflows and lesions including the suprachiasmatic nucleus eliminate these changes in rats.

Neurons in the suprachiasmatic nucleus (SCN) are suggested to be involved in the mechanism of glucose homeostasis. This mechanism was examined by studies on the effect of illumination on the activity of autonomic efferents to the adrenals, pancreas and liver. Exposure of one eye of anesthetized rats to light enhanced the efferent activity of the adrenal nerve and suppressed that of vagal pancreatic and hepatic nerves. No change in efferent activities of these nerves was observed on light-stimulation of rats with lesions that included the bilateral SCN. These findings indicate that light signals modulate visceral functions including metabolic processes through the retinohypothalamic tract probably via the SCN to autonomic efferent pathways innervating visceral organs.

Adrenal Glands↗
PubMed1992

Measurement of sound-pressure distribution in replicas of the oral cavity.

The spatial distributions of sound pressure in artificial oral cavities were measured to examine the characteristics of wave propagation in the vocal tract. The measurement was performed with plaster replicas of the oral cavity, and pure tones were used as the driving signals to obtain both amplitude and phase distributions at varied frequencies. Plane-wave propagation, which has been widely assumed for speech production models, was examined from the measured spatial distributions of sound pressure. Trajectories of media particles and vectorial maps of acoustic intensity, which can be computed from the measured pressure distributions, were also presented to visualize the acoustic field in the oral cavity. The results showed that at certain frequencies there existed points where sound pressure was absolutely zero, with the phase spatially circulating around them. Up to about 4 kHz, except at these certain frequencies, the wave front was almost one-dimensional, though an amplitude gradient was seen in the vertical direction.

Acoustics↗
PubMed1992

Osteoclastic features of multinucleated giant cells responding to synthetic hydroxyapatite implanted in rat jaw bone.

Multinucleated giant cells (MGCs) that responded to synthetic hydroxyapatite (HAP) implanted in rat mandibles were studied with electron microscopy. HAP used in this study sintered at 200 degrees C (HAP200) and at 125 degrees C (HAP1250) after the synthesis by a wet method. One to three weeks after the intraosseous implantation of HAP, MGCs responding to HAP200 had not only well-developed ruffled border and the clear zone but well-developed perinuclear Golgi complex, many mitochondria and vesicles in their cytoplasms. MGCs responding to HAP1250 had the clear zone, but not the ruffled border although they showed similar cytoplasmic features to those of MGCs responding to HAP200. They merely extended short slender cytoplasmic processes to HAP1250. These results suggest that although osteoclast-like MGCs respond to HAP implanted in the bone, the development of the ruffled border-clear zone system depends on physicochemical properties of HAP.

Animals↗
PubMed1992

[Molecular biological study on multifocal infection of HPV in uterine cervix, vagina and vulva].

Vaginal and vulvar scrapes from 30 patients which have HPV types 16 or 18 positive cervical neoplasia (13 of mild dysplasia, 5 of moderate dysplasia, 4 of severe dysplasia, 3 of carcinoma in situ, and 5 of invasive carcinoma) were examined by the polymerase chain reaction (PCR), to detect amplified E7 gene of HPV types 16 and 18 DNA sequences. In 24 vaginal and 15 vulvar scrapes, the same type of HPV as in cervical scrapes was detected. The frequencies of HPV DNA in vaginal and vulvar scrapes for histological diagnosis of cervical neoplasia were 84.6% (11/13) and 53.8% (7/13) in mild dysplasias, both were 100% (5/5) in moderate dysplasias, 75% (3/4) and 25% (1/4) in severe dysplasias, 66.7% (2/3) and 33.3% (1/3) in CISs, and 60% (3/5) and 20% (1/5) in invasive carcinomas, respectively. The results of vulvar scrapes showed that the frequency of HPV DNA in mild and moderate dysplasias was significantly higher than that in severe dysplasias, CISs and invasive carcinomas (p < 0.05). We suggest that, in addition to the investigation for the natural history of HPV infection, cell dynamics, local immunological status and any other factors in the HPV-infected lesion must be investigated to clarify the carcinogenesis of HPV in the uterine cervix. Furthermore, HPVs detected in the vagina and vulva were thought to have disappeared without reaching an integrated form during the follow-up of cervical neoplasia with HPV infection over a long period.

DNA, Viral↗
PubMed1992

[A multicenter, fixed-flexible dose study of terazosin hydrochloride in the treatment of symptomatic benign prostatic hypertrophy].

In this study the multicenter, fixed-flexible dose regimen was taken to evaluate the effective dose range of Terazosin for the treatment of micturition disturbance in benign prostatic hypertrophy (BPH) and to clarify the characteristics of patients who are more responsive to Terazosin therapy. After a 1-week washout (placebo) the first two weeks 1 mg/day of Terazosin was administered, then depending on efficacy of subjective symptoms, Terazosin doses were increased up to 2 mg/day and 4 mg/day at intervals of two weeks. After six weeks the final efficacy and safety were assessed. The subjective symptom improvement rate was 18.5% by 1 mg/day, 55.6% by 2 mg/day and 65.4% by 4 mg/day cumulatively. The objective symptom improvement rate were 13.2% by 1 mg/day, 42.1% by 2 mg/day and 50.0% by 4 mg/day cumulatively. The global improvement rate was 14.5% by 1 mg/day, 50.0% by 2 mg/day and 61.8% by 4 mg/day cumulatively. The patients who had a higher subjective symptom score in the lead-in period were more improved rather than those who had a lower score. In objective symptoms, voided volume, maximum flow rate (MFR), MFR nomogram score and average flow rate improved and the ratio of residual urine volume decreased. There was no relationship between clinical improvement on either subjective or objective symptoms and prostatic weight. Adverse reactions, such as dizziness, vertigo, tinnitus, nausea and blurred vision; were seen in 10 cases. In conclusion Terazosin was effective and well tolerated for the treatment of patients who had micturition disturbance with BPH in the dose range of 2 to 4 mg/day.

Adrenergic alpha-Antagonists↗
PubMed1992

[Molecular biological study on the overexpression of c-myc gene in uterine cervical carcinomas].

The expression of mRNA for c-myc gene was investigated in 30 cases of human uterine cervical carcinoma by Northern blot hybridization, and c-myc gene amplification was also examined by Slot blot hybridization. Overexpression of c-myc gene was detected in one (7.7%) of 13 cases of carcinoma in situ (stage 0), one (10.0%) of 10 stage I and 4 (57.1%) of 7 stage II uterine carcinoma, and c-myc gene amplification was detected in 2 cases (6.7%) in which c-myc gene overexpression was also found. The patient whose c-myc mRNA level was more than 10 times as high as in normal uterine cervical tissue relapsed and died within 2 years after the first treatment. Our results suggest that the overexpression of c-myc gene occurred more frequently in advanced than in early uterine cervical carcinoma and that it might be useful in prognosing cervical cancer.

Adenocarcinoma↗
PubMed1991

Ameloblastic carcinoma: case report and review.

The histologic classification for odontogenic carcinomas is still under revision; thus, the differentiation between the terms "malignant ameloblastoma" and "ameloblastic carcinoma" has not been definitely stated. Nevertheless, it is recommended to reserve the former for those lesions that, in spite of an apparently innocuous histology, have given origin to metastatic growths, and to apply the latter for those ameloblastomas in which there is histologic evidence of malignancy in the primary, recurrent or metastatic lesions. A case of an ameloblastic carcinoma in the mandible is presented. Histologically, it was characterized by areas with features of a typical ameloblastoma and areas with anaplastic appearances.

Ameloblastoma↗
PubMed1991

Assessment of the long-term results of ileocecal conduit urinary diversion.

We reviewed our 12.5-year experience with ileocecal conduit (ICC) and report the long-term results of 147 cases of ICC compared with those of our 102 cases of ileal conduit (IC). We usually performed ICC following total cystectomy for carcinoma of the bladder, while we chose IC in cases of high stage or recurrent malignancies. The average follow-up period was 41.7 months in the ICC group and 28.8 months in the IC group. The postoperative mortality (6.1%) and the incidence of early complications (21.1%) in the ICC group were comparable with the reported incidences for IC. In the later period, stomal problems were most frequently encountered. Urinary tract complications are important because they affect renal function in the course of a long period of time. Excretory urogram showed a satisfactory result and serum creatinine remained within the normal limits even in patients followed up for a long time in both groups. The incidences of pyelonephritis and urinary stones in the ICC group were 13.6 and 5.4%, respectively. We had expected a much lower incidence of these complications and ICC could not cover all the drawbacks of IC. However, at present, there is no ideal or perfect method of urinary diversion, ICC should be one of the acceptable options which has a satisfactory long-term result.

Adolescent↗
PubMed1991

Estimation of the right ventricular volume overload in children with atrial septal defect by body surface mapping.

To investigate the possibility of estimating the right ventricular volume overload in atrial septal defect (ASD) by body surface mapping (BSM), 45 children with ASD were included in the present study. The breakthrough minimum (BTM) appeared later and more leftward in ASD subjects than in the normal controls. Neither the length of the delay in the appearance of the BTM nor the extent of its leftward deviation was significantly correlated with the pulmonary and systemic flow volume ratio (Qp/Qs), obtained by cardiac catheterization. Therefore neither could be used as the parameter of the right ventricular volume overload. sigma R, Rmax (D3 + D4) + magnitude of S max (H4 + H5) and "T dep", the sum of the absolute values of the departure indices (DIs) in the G4, G5, H4 and H5 leads, and the DIs in the J5, J6, K5, and K6 leads in T departure Map, correlated with the Qp/Qs significantly (r = 0.62, 0.68, 0.69, respectively). Accordingly, they might be useful for estimating the right ventricular volume overload. The subjects were divided into 3 groups according to their Qp/Qs. Discriminant analysis between these 3 groups was then performed, using Rmax (D3), magnitude of S max (H4), and T dep as the variables. The accuracy of this discrimination was 82.2%. The results suggest the possibility of estimating the severity of ASD by BSM.

Adolescent↗
PubMed1991

[Clinical study of extracorporeal shock wave lithotripsy for stones in solitary kidney].

Extracorporeal shock wave lithotripsy (ESWL) treatment was performed on 17 patients with a solitary or sole functioning kidney from August 1986 to April 1988. Some patients with renal stone had a double pig tail catheter to protect the stone street and those with ureteral stones had a ureteral balloon occlusion catheter to raise the efficiency of fragmentation placed prior to ESWL as much as possible. Combined manipulation with such an instrument as nephrostomy tube to wash out residual stone fragments or endoscopic operation were performed. Despite of these devices, ESWL treatments for staghorn calculi and cystine stones were troublesome in solitary kidneys. After follow up ranged from 9 to 602 days (mean 87.6 days), 10 patients (58.8%) were stone free. ESWL treatment is safe and effective for solitary kidneys. We recommended premedication and pretreatment by ureteral stenting in patients with a solitary kidney.

Adult↗
PubMed1991

[In situ hybridization study on the detection of HPV DNA in adenocarcinoma and adenosquamous carcinoma of the uterine cervix].

Human papillomavirus (HPV) types 16 and 18 have been found closely associated with squamous cell carcinoma and related lesions of the uterine cervix. In order to investigate the relationship between HPV and adenocarcinoma and adenosquamous carcinoma of the uterine cervix, formalin-fixed, paraffinembedded tissues prepared from 38 cases consisting of 30 cases of adenocarcinoma and 8 cases of adenosquamous carcinoma were examined for the presence of HPV DNA by in situ hybridization with digoxigenin labeled HPV 6/11, 16, 18 DNA probes. HPV DNA was localized on the nuclei of the cancer cells in adenocarcinoma and adenosquamous carcinoma. HPV DNA was detected in 13 cases (43.3%) of adenocarcinoma and 4 cases (50.0%) of adenosquamous carcinoma, and HPV type 18 DNA was detected in 13 cases (34.2%) of adenocarcinoma and adenosquamous carcinoma. These findings suggest an association between HPV, especially HPV type 18, and adenocarcinoma and adenosquamous carcinoma of the uterine cervix.

Adenocarcinoma↗
PubMed1991

[Amplified DNA detection of HPV types 16 and 18 DNA in cervical scrapes by polymerase chain reaction].

Cervical scrapes from 43 patients (12 with chronic cervicitis, 13 with dysplasia, 11 with carcinoma in situ and 7 with invasive carcinoma) were examined by the polymerase chain reaction (PCR), to detect the amplified E7 gene of the HPV types 16 and 18 DNA sequence. HPV types 16 and/or 18 DNA were detected in 25 of 43 cases by the PCR (type 16 in 16, type 18 in 8, and both types 16 and 18 in 1). In comparison with the results for histological grades, the positive rate significantly increased as the grade of cervical dysplasia became higher. All cases were also examined with a HPV detection kit, the "Vira Pap" which contains 32P-labeled mixed RNA probes complimentary to HPV types 6, 11, 16, 18, 31, 33, 35 DNA. Six of 18 cases in which HPV DNA were not detected by the Vira Pap were positive for HPV types 16 and/or 18, so that the PCR was a highly sensitive method compared to the Vira Pap. The PCR has some advantages: 1. it requires only a small amount of specimens and 2. paraffin-embedded sections can also be used. We suggest that the PCR is a useful method for the screening and for retrospective investigation of HPV infection.

Adult↗
PubMed1990

Clinical profile of Japanese dialysis patients with diabetic nephropathy, diagnosed as having diabetes before the age of thirty.

Diabetic nephropathy is the leading cause of death in young diabetic patients. There are a large number of patients with non-insulin-dependent diabetes mellitus (NIDDM) who are diagnosed before the age of 30 in Japan. We investigated 36 patients with young-onset diabetes who started dialysis between 1978 and 1987 in our hospital. Of the 36 patients, 12 (33.3%) were classified as having insulin-dependent diabetes mellitus (IDDM), 22 (61.1%) had NIDDM, and 2 (5.6%) could not be classified clinically. The percentages of the different types of diabetes in our series of dialysis patients were almost identical with those in Nagai's series of 551 diabetic patients diagnosed before the age of 30 at the Diabetes Center of Tokyo Women's Medical College from 1976 to 1981. The present study showed the young-onset NIDDM in Japan was associated with almost the same incidence of end-stage diabetic nephropathy as was IDDM. However, the number of NIDDM patients diagnosed under 30 years of age was almost double that of IDDM patients. Thus, we have to pay greater attention to the development of diabetic nephropathy in young-onset NIDDM patients than has been thought necessary in the past.

Adolescent↗
PubMed1990

[Study on the localization of human papillomavirus DNA in the vulvar disease by means of in situ hybridization].

We investigated human papillomavirus (HPV) DNA of vulvar diseases obtained from 18 cases of condyloma acuminatum, 3 cases of hyperplastic dystrophy without atypia, 4 cases of lichen sclerosus, 4 cases of Bowenoid papulosis, one case of Bowen disease and 8 cases of squamous cell cancer by in situ hybridization with biotinylated HPV 6, 11, 16 and 18 DNA probes. The results of in situ hybridization analysis showed that HPV 6/11 was positive in 94.4% (17/18) of condyloma acuminatum. In 17 cases of HPV 6/11 positive condyloma acuminatum, 3 cases were positive for HPV 16 and one for HPV 18, respectively. HPV 16 was positive in 75.0% (3/4) of Bowenoid papulosis and one case of Bowen disease was positive for HPV 18. In two cases of Bowenoid papulosis which were positive for HPV 16, cervical carcinoma in situ containing HPV 16 DNA sequences was also found during the follow up period. In 8 cases of squamous cell cancer, 2 cases were positive for HPV 18, one for HPV 16 and one for HPV 6/11. All cases of hyperplastic dystrophy without atypia and lichen sclerosus were negative for HPV DNA. Our results suggested HPV is closely associated with vulvar neoplasia.

Adolescent↗