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Biomedical subjects

A Aoki

Publications and source records attributed to A Aoki.

At least 55 records · Page 3Linked to original sources
PubMed2000

[Prototype of light source for photodynamic therapy in Centre of Electron Microscopy].

The Photodynamic Therapy (PDT) is a cancer treatment based on specific accumulation of a photosensitizer in the malignant tissue and its subsequent irradiation at appropriate wave lengths induce the production of oxygen singlets responsible for peroxidation of cell organelles and cell death. A prototype of a 630 nm non coherent light source designed and constructed at the Centre of Electron Microscopy of The Cordoba National University allowed a successful application of PDT, in nonmelanoma skin tumors, for the first time in this Country. A topical treatment with 20% delta aminolevulinic acid (ALA) in aqueous solution was applied in 100 lesions of actinic keratosis of 27 patients. The results obtained in this study were the following: Complete Remission (RC) 84%, Partial Remission (RP) 10%, No Response (SR) 0% and No data (SD) 6%. In the latter group are included those patients who did not return for reevaluation. The high efficiency plus the excellent cosmetic response and low aggressiveness, make the PDT the method of choice treatment of this skin pathology. In addition to be no invasive and well tolerated, the prototype of light source used in this study, was remarkably effective.

Aged↗
PubMed2000

[Two cases of acute lupus peritonitis].

We report two cases of systemic lupus erythematosus (SLE) diagnosed when acute peritonitis was appeared. Case 1 was a 20 year-old woman suffering from stomachache and right lower abdominal pain. Case 2 was a 40 year-old woman with diarrhea, epigastralgia, pollakisuria. In both cases, their peritoneal fluids were exudative with positive autoantibodies. After high dose steroid therapy, abdominal symptoms and ascites improved promptly. However, due to the complication of lupus nephritis, additional therapy was necessary. To characterize the feature of lupus peritonitis (LP), we examined the clinical and laboratory findings of LP from the literature. In patients with acute LP, abdominal pain, vomiting, diarrhea were significantly more common compared with chronic LP patients (P < 0.05), and fever, arthritis, central nervous system involvement and cystitis were more common. In patients with chronic LP, pleural effusion and pericardial effusion were more common compared with acute LP patients. Gastrointestinal manifestations such as abdominal pain, vomiting and diarrhea were more common in patients with acute LP compared with patients with chronic LP. Most patients with chronic LP were asymptomatic, ascites and serositis being the only clinical findings. The response to steroid therapy was better in acute LP.

Acute Disease↗
PubMed2000

[A case of bitemporal epilepsy that was well controlled after unilateral lobectomy].

Here we report a case of bitemporal epilepsy that was well controlled after unilateral temporal lobectomy. The patient was a 31-year-old woman, who was born in an asphyxia state and had a history of a febrile convulsion. Complex partial seizure(CPS) preceded by abdominal aura appeared at the age of three. Despite anticonvulsant medication, the seizures gradually increased in frequency and sometimes developed into secondary generalized convulsions. Her scalp electroencephalogram(EEG) showed interictal spikes and seizure activities arising from the bilateral temporal lobes. No apparent lateralities in regard to the size or blood flow at the hippocampus were detected by MRI and SPECT studies. Intracranial EEG monitoring revealed that 80% of the clinical seizures originated from the left mesial temporal lobe, which was the non-dominant side for speech and memory functions as demonstrated by Wada test. Therefore, we performed a left temporal lobectomy that resulted in the complete disappearance of CPS. The present case exemplified the usefulness of intracranial EEG monitoring to clarify the dominant epileptic focus for surgery.

Adult↗
PubMed1999

Prolactin secretory bypath exposed in cultured lactotrophs.

In the present report, the prolactin secretory pathways were re-examined in cultured lactotrophs submitted to various experimental conditions of stimulation, inhibition and/or alteration of the intracellular flow of the synthesis and release of prolactin. Primary cultures of rat pituitary cells stimulated with thyrotropin-releasing hormone, or inhibited with either cycloheximide or dopamine in the presence or absence of 0.1 microg/ml brefeldin A, were used. The radioimmunoassay quantification of released and intracellular prolactin was correlated with ultrastructural and immunocytochemical studies. Brefeldin A diminished significantly the secretion and the intracellular content of prolactin 4 h after application, while morphological effects were seen starting from 30 min. The drug did not modify the response to thyrotropin-releasing hormone (120% increment). The simultaneous incubation of brefeldin A with cycloheximide or dopamine diminished the released prolactin concomitant with a lower (cycloheximide) or greater (dopamine) hormonal intracellular prolactin content with respect to brefeldin A. The combined treatment cycloheximide-dopamine inhibited prolactin secretion. The ultrastructural and immunocytochemical features of lactotrophs supported these radioimmunoassay data. These results revealed that prolactin release in vitro in the presence or not of brefeldin A is dependent on either: the neosynthesized hormone that can be inhibited by cycloheximide, and the hormone stored in granules, the exocytosis of which was blocked by dopamine, indicates the contribution of both constitutive and regulated pathways in the secretory process. The brefeldin A blockade of the intracellular transport also disclosed morphological evidence of an alternative pathway of prolactin secretion through vesicles originated in the rough endoplasmic reticulum bypassing the Golgi complex.

Animals↗
PubMed1999

Distribution of mefE and ermB genes in macrolide-resistant strains of Streptococcus pneumoniae and their variable susceptibility to various antibiotics.

From February to October 1995, 62 erythromycin-resistant strains of Streptococcus pneumoniae isolated at Yamanashi Red Cross Hospital were tested to determine their susceptibility to various macrolides, subjected to resistance induction tests by the disc diffusion method and analysed for genes encoding resistance to macrolides (ermB and mefE). On the basis of resistance induction testing, the isolates were classified as having either inducible (59.7%) or non-inducible (40.3%) macrolide resistance. The ermB gene was always detected in resistance-inducible type isolates, either alone or in combination with mefE. The mefE gene alone was found only in non-inducible type isolates. Isolates with non-inducible resistance (those with only the mefE gene) had an intermediate level of resistance to 14-membered macrolides, and were susceptible to rokitamycin, a 16-membered macrolide. According to NCCLS guidelines, 9.6% of S. pneumoniae strains were judged to be susceptible to penicillin, 62.9% of reduced susceptibility and 27.4% penicillin resistant. No correlation was detected between the presence of particular macrolide-resistance genes (ermB, ermB + mefE, or mefE) and resistance to penicillin G.

Anti-Bacterial Agents↗
PubMed1999

Coronary artery bypass grafting in the acute phase after renal transplantation: report of a case.

To the best of our knowledge, only 3 cases of coronary artery bypass grafting (CABG) performed under cardiopulmonary bypass (CPB) on patients in the chronic phase after renal transplantation have been reported in Japan. The first case of a patient who underwent CABG in the acute phase after renal implantation in Japan is herein described. Perioperatively, oral immunosuppressive agents were discontinued and they were given intravenously. Cyclosporin A (Cy-A) was administered via a continuous intravenous infusion in the acute phase after renal transplantation and closely monitored, because the blood concentration of Cy-A can vary a great deal during the perioperative period. This case report serves to demonstrate that as long as appropriate immunosuppressive drugs are perioperatively administered, CABG under CPB can be safely performed on patients who have undergone renal transplantation without subsequent rejection, infection, or renal damage, even during the acute phase.

Administration, Oral↗
PubMed1999

Sellar chondroma--case report.

A 12-year-old boy presented with right visual disturbance. Skull radiography and computed tomography (CT) showed an irregular deformity of the sella turcica, hypertrophic change of the dorsum sellae, and an inhomogeneously calcified mass in the sella turcica. Magnetic resonance (MR) imaging demonstrated the mass lesion filled the hypophyseal fossa, and extended to the dorsum sellae, right cavernous sinus, and right suprasellar region. The Dolenc pterional combined epidural and subdural approach was carried out. The histological diagnosis was chondroma. Sellar chondroma requires relief of the compression to the chiasm or optic nerve as soon as possible, so partial resection can still be beneficial. However, follow-up MR imaging or CT, visual examination, and control of pituitary dysfunction are required after the operation.

Child↗
PubMed1999

[Analysis of the long-term prognosis for conjunctival malignant melanomas in Japan].

PURPOSE: To investigate the long-term prognosis for primary conjunctival malignant melanomas in Japan. MATERIALS & METHODS: We conducted a survey of 61 cases which had been reported in a 38-year period (1959 to 1996). We gathered information regarding the survival of patients, the post-operative follow-up period, the causes of death, and recurrences. Answers were obtained segarding 51 cases (84%). Detailed progress was identified in 23 of these cases. The survival rates were calculated using the Kaplan-Meier method. RESULTS: The survival rates were 95.1% after 1 year, 72.9% after 3 years, and 53.4% after 5 years. These values are relatively low compared with those reported in Europe and the United States.

Adolescent↗
PubMed1999

[Investigation of plasma levels of etodolac and urine PGE2 in patients with rheumatoid arthritis].

13 women patients (containing high-aged, mean age 71.9 years) with rheumatoid arthritis (RA) (10 with normal renal function and 3 with moderate renal insufficiency) participated in a 5-day study to assess the effects of etodolac on renal function and the necessity of dose adjustment. After no drug-free day, etodolac, 200 mg b.i.d. was started. The plasma levels of etodolac were similar in both normal control in phase I studies and throughout this study. Although the mean urine PGE2 concentration in renal insufficient group was significantly lower than that of normal renal function group, the mean urine PGE2 concentration in after etodolac administration was not different from that in before its administration in each group. This result suggested that renal adverse reactions with etodolac were low in incident. Moreover, it was required to consider that glucocorticoid might influence renal and/or hepatic excretion of etodolac. In this study the glucocorticoid was tend to be administrated in the patients with moderate renal insufficiency. Those glucocorticoid group showed lower levels of etodolac in blood serum (monitored by AUC0-8, day 4 Cmin and day 5 Cmin) than non-glucocorticoid group did, but not significantly. Interestingly, there is a negative correlation (r = -0.442) between AUC0-8 at day 1 and urine PGE2 at day 5 in glucocorticoid group. The levels of etodolac in blood serum in normal renal function group were also not significant in difference from that in the moderate renal insufficient group. These results suggest that the dose adjustment of etodolac in high-aged RA patients with moderate renal insufficiency can be excluded.

Aged↗
PubMed1998

[Surgical repair of coronary sinus type partial anomalous pulmonary venous drainage with intact atrial septum].

We experienced a rare form of PAPVD without atrial septal defect. The patient was a 33-year-old male and he was referred to our institute because of mild right pulmonary congestion detected by a routine chest X-P. Enlarged coronary sinus, right atrium and right ventricle were documented by UCG. The Qp/Qs was 1.9 and pulmonary artery pressure was 38/7 mmHg (mean: 17 mmHg) by cardiac catheterization. Selective pulmonary angiogram showed that all right pulmonary veins drained into the coronary sinus without evidence of an atrial septal defect. Enhanced chest CT clearly demonstrated the connection between the right pulmonary vein and the coronary sinus. Intracardiac repair without atrial baffle was carried out under hypothermic cardiopulmonary bypass. Under cardiac arrest with cardioplegia, the common wall between the right pulmonary vein and the left atrium was incised and the connection between the right pulmonary vein and the left atrium was established. The flap made by this incision was brought posterior to close the right pulmonary vein opening to the coronary sinus. The postoperative course was uneventful and the minimum diameter of the right pulmonary vein was found to be 15.5 mm by a postoperative pulmonary artery angiogram. This operative method without an atrial baffle could be an alternative procedure for coronary sinus type PAPVD.

Adult↗
PubMed1998

[Norwood procedure to hypoplastic left heart syndrome].

Since March 1992, 25 neonates and small infants with HLHS have undergone a modified Norwood procedure. The mean age and weight at operation were 17 days (2 days-2 months) and 2.7 kg (1.6-3.3 kg). Isolated cerebral and/or myocardial perfusion (ICMP) with direct anastomosis of aorta and pulmonary artery was utilized since January 1995 to 16 patients. Under median sternotomy, PTFE graft (usually 3.0-3.5 mm) was anastomosed to the brachiocephalic artery and the arterial cannula was inserted to this PTFE graft. The left carotid and the left subclavian arteries were snared and a clamp was placed on the aortic arch just distal to the brachiocephalic artery. This allowed blood to enter the brain and the coronary arteries, keeping the brain perfused and the heart-beating. After reconstruction of distal aortic arch, a single dose of crystalloid cardioplesia was infused and the rest of the arch was reconstructed. There were 14 early deaths (56%) and 4 late deaths (16%). Bidirectional Glenn procedure was performed to 5 patients with 1 death. Three patients underwent modified Fontan procedure without mortality. Mean aortic cross clamp time was 24 min. and mean ICMP time was 32 min. There was no neurologic complications. In conclusion, isolated cerebral and/or myocardial perfusion may offer an advantage of protecting the brain and myocardium during arch in Norwood procedure.

Aorta↗
PubMed1998

Apoptotic and non-apoptotic cell death in hormone-dependent glands.

The proliferation of cells and cell death are involved in the maintenance of appropriate tissue homeostasis. In the present study, two different mechanisms of cell death were identified in the prostate and pituitary glands when morphological data, fragmentation of DNA, and TUNEL labelling of apoptotic nuclei were compared. Typical cell death by apoptosis was identified by morphological and molecular approaches in the prostate after orchidectomy. By contrast, neither DNA fragmentation nor TUNEL labelling were found in dead cells occurring in the pituitary gland after interruption of lactation. Regressing lactotrophs were characterised by condensation and disruption of the cytoplasmic matrix, but preserved intact nuclei until advanced stages of regression. Degenerating "dark" cells comparable to those described in the pituitary were also seen coexisting with typical apoptosis in the prostate epithelial lining of orchidectomised rats. Both forms of cell death could be clearly differentiated, because dark cells suffer severe alterations of cytoplasmic organelles while maintaining the integrity of the nucleus. In contrast, apoptotic cells present well-preserved cytoplasmic organelles, but grossly disrupted nuclei with fragmentation and condensation of chromatin.

Animals↗
PubMed1998

Effect of acarbose on postprandial lipid metabolism in type 2 diabetes mellitus.

The effect of acarbose, an alpha-glucosidase inhibitor, on postprandial glucose and lipid metabolism was investigated in patients with type 2 diabetes mellitus. Twenty patients (10 men and 10 women) with type 2 diabetes mellitus were studied. A test meal was taken with or without 100 mg of acarbose. The levels of plasma glucose, and serum immunoreactive insulin, lipids, apolipoproteins, and remnant-like particle cholesterol were investigated. Acarbose inhibited the postprandial increase of both plasma glucose and serum immunoreactive insulin. Acarbose also significantly suppressed the increase of serum triglycerides at 60, 90, and 120 min (P < 0.05 to P < 0.01), and the increase of serum remnant-like particle cholesterol at 60 and 120 min (P < 0.05). Acarbose inhibited the postprandial decline of apolipoprotein C-II, and decreased the postprandial serum apolipoprotein C-III level. These results suggest that acarbose may improve postprandial hyperlipidemia as well as postprandial hyperglycemia in patients with type 2 diabetes mellitus.

Acarbose↗
PubMed1998

Mechanisms in progestin antagonism of pituitary tumorigenesis.

Chronic exposure of F344 rats to diethylstilbestrol (DES) induces pituitary tumors (DES-T) composed of proliferating lactotrophs. Presently, we studied the effect of progestins on parameters related to tumor growth and function, due to previous evidences of progesterone antagonism of pituitary tumorigenesis acting at pituitary and hypothalamic levels [Piroli, G., Grillo, C., Ferrini, M., Lux-Lantos, V. and De Nicola, A. F., Antagonism by progesterone of diethylstilbestrol-induced pituitary tumorigenesis in Fischer 344 rats: Effects on sex steroid receptors and tyrosine hydroxylase mRNA, Neuroendocrinology, 1996, 63, 530-539]. In search of a quantitatively more important effect, animals bearing DES-T were treated with synthetic progestins. Competition assays using DES-T as source of progestin receptors indicated that levonorgestrel (LNG), gestodene and R5020 showed higher affinities (IC50 1-2 nM) than progesterone, norethisterone and medroxyprogesterone (IC50 10-25 nM). Treatment with LNG reduced DES-T weight by 45%, and serum PRL by one half. Small (monomeric) and big (polymeric) PRL increased 5- and 2.5-fold, respectively, in DES-T in comparison with pituitaries of ovariectomized (OVX) rats. However, LNG produced no changes indicating that synthesis and storage of PRL was conserved in rats receiving both hormonal treatments. DES induced a 15-fold increase in cell proliferation, measured as bromodeoxyuridine incorporation into cell nuclei, in comparison to OVX rats, while LNG treatment of DES-T bearing rats reduced this index by 72%. Electron microscopic images showed that LNG markedly reduced hypertrophy and hyperplasia of lactotropes, increasing the proportions of degenerating cells and cells of high electronic density with alterations of cytoplasmic organelles. However, histopathological signs of apoptosis were absent. Therefore, reduced cell proliferation and non-apoptotic cell death are part of the mechanisms employed by progestins to antagonize tumorigenesis at the pituitary level. The results may open a new therapeutic strategy for treatment of PRL secreting adenoma in humans.

Animals↗
PubMed1998

Residual effects of thyroid hormone on secretory activity of somatotroph population.

In the present experiments the effects of the interruption of a prolonged T3 treatment on somatotroph population and GH synthesis and secretion were studied. The treatment with pharmacological doses of T3 provokes marked ultrastructural changes in somatotrophs compatible with a stimulated synthesis of GH. These results can be correlated with the significant increase in pituitary GH content and the normal values of serum GH. Twenty-four hours after T3 withdrawal, somatotrophs exhibited a marked depletion of secretory granules by exocytosis. These changes were concurrent with a significant discharge of pituitary GH and a two-fold increase in GH serum levels. The serum concentrations attained the highest values on the second and the third day after the T3 suppression, while the pituitary GH contents recovered the control levels. Morphometry of somatotroph population revealed a clear proliferation of cells and increased areas immunostained for GH, 24 h after withdrawal of the T3 treatment. The effects of T3 on somatotrophs were persistent for several days and at least five days were required for all parameters to return to control values. These results provide a new insight on the residual activity of thyroid hormones on both functional activity and morphological organization of somatotrophs.

Animals↗
PubMed1998

Comparison between Er:YAG laser and conventional technique for root caries treatment in vitro.

Effective ablation of dental hard tissues by means of the erbium-doped:yttrium-aluminum garnet (Er:YAG) laser has been reported recently, and its application to caries removal and cavity preparation has been expected. However, few studies have investigated the capability of the Er:YAG laser to treat caries. In the present study, the effectiveness of caries removal by using an Er:YAG laser in vitro was compared with that of conventional mechanical treatment. Thirty-one extracted human teeth with root caries were used. Half of the caries in each tooth was treated with the Er:YAG laser, and the other was removed with a conventional bur or was left untreated as a control. Laser treatment was performed by means of a combination of contact and non-contact irradiation modes with cooling water spray, with a new fiber delivery and contact probe system. Conventional bur treatment was conducted by means of a low-speed micromotor. Measurements of the time required for caries removal, histopathological observations of decalcified serial sections, scanning electron microscope (SEM) observations, and hardness measurements of the treated cavity-floor dentin were performed for each treatment. Due to the careful irradiation technique, a longer treatment time was required for the complete removal of carious dentin by the Er:YAG laser. However, the Er:YAG laser ablated carious dentin effectively with minimal thermal damage to the surrounding intact dentin, and removed infected and softened carious dentin to the same degree as the bur treatment. In addition, a lower degree of vibration was noted with the Er:YAG laser treatment. The SEM examination revealed characteristic micro-irregularities of the lased dentin surface. Our results show that the Er:YAG laser system is promising as a new technical modality for caries treatment.

Dental Cavity Preparation↗