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Biomedical subjects

T Maeda

Publications and source records attributed to T Maeda.

At least 793 records · Page 44Linked to original sources
PubMed1993

[Serial changes in QT interval during acute myocardial infarction: comparison of QT interval changes of reperfused cases and non-reperfused cases].

The serial changes in QT intervals during the course of acute myocardial infarction are of interest from the standpoint of the electrocardiogram itself, the development of ventricular tachyarrhythmias, residual cardiac function, and the prognosis of the patients. However, only sparse literature has dealt with this issue because it is difficult to obtain ECGs for analysis, and multiple factors influence the QT interval including the degree of reperfusion, electrolyte imbalance, hemodynamic changes and drugs which alter the QT interval. The ECGs of patients with acute myocardial infarction who underwent reperfusion therapy were analyzed: Sixteen consecutive patients were enrolled in this study, 9 with TIMI grade II and III (TIMI: the thrombolysis in myocardial infarction study group criteria) and 7 with TIMI grade 0, myocardial infarction with (9) and without (7) reperfusion. Patients with collaterals, TIMI grade I, hypertrophic cardiomyopathy, electrolyte imbalance, Ia antiarrhythmic drugs, beta adrenoreceptor blockades, atrial fibrillation, and intraventricular conduction disturbances were excluded from the study. Serial ECG recordings were performed at 3, 6, 9, 12, 24, 48, and 72 hours after the onset of myocardial infarction. One week after and one month after the onset, the ECGs were recorded. Patients who exhibited reocclusion on their arteriograms in the chronic phase were also excluded from the study. Measurements of the QT intervals were performed at the ischemic lead (II in the standard limb lead in inferior infarction and V2 in anteroseptal infarction), and values were averaged from 5 consecutive QRS complexes according to Lepeschkin's method and corrected using Bazett's method. The left ventricular ejection fraction (LVEF) and percent fractional shortening (FS) in segments 2, 3, 4 or 5 were calculated from the ventriculogram in the chronic phase. The QT interval revealed a lengthening with its peak within 12 hours after the onset and it became shorter thereafter in reperfused patients. In patients without reperfusion, the QT interval became progressively prolonged without showing a peak point, up to one month. LVEF and FS were significantly higher values in patients with reperfusion than in those without reperfusion. In conclusion, in patients with reperfusion, the QT interval was transiently prolonged and later shortened with improved LVEF and FS than in patients without reperfusion.

Adult↗
PubMed1993

Torsades de pointes associated with acquired long QT syndrome: observation of 7 cases.

We examined the clinical characteristics and electrocardiographic findings of 7 patients having the acquired long QT syndrome who developed torsades de pointes while receiving no antiarrhythmic drugs. A total of 43 episodes of torsades de pointes were documented among these patients. Underlying heart diseases were present in 6 patients and hypopotassemia (< or = 3.3 mEq/l) in 4. Four had bradycardia (< or = 52 beats/min) immediately before the development of torsades de pointes. The QTc intervals measured immediately before the episodes of torsades de pointes were significantly longer than those 6-24 hours before the episodes (0.69 +/- 0.10 vs 0.56 +/- 0.10 sec, p < 0.05), while heart rates did not differ significantly between these 2 periods (54 +/- 12 vs 58 +/- 15 beats/min). The ventricular rate of torsades de pointes was 192 +/- 24 beats/min. A "long-short initiating cycle" was noted in all 43 episodes, and the initiating premature ventricular beat (PVB) showed the "R on T(U)" phenomenon in 42 of the episodes. A notched T-U complex due to a prominent slow wave (U wave) at the end of the T wave was noted in 5 patients immediately before the episodes of torsades de pointes. Prolongation of the preceding RR interval was directly related to the increase of the U wave amplitude, which caused an increased likelihood of the occurrence of PVBs near the peak of the U wave. Torsades de pointes developed from the largest U wave. Direct current cardioversion was transiently effective for treating torsades de pointes, and intravenous lidocaine, atropine and verapamil were effective in some cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Serum thyroid hormone levels correlate with cardiac function and ventricular tachyarrhythmia in patients with chronic heart failure].

The relationship between cardiac function and serum thyroid hormone levels was investigated in 41 patients with chronic heart failure (25 men and 16 women, mean age 63.7 +/- 11.1 years) and 15 normal subjects (5 men and 10 women, mean age 55.5 +/- 12.2 years). Patients with apparent thyroid disease were excluded from the study. All patients were evaluated according to the New York Heart Association (NYHA) classification using echocardiography, cardiothoracic ratios, mean daily heart rates calculated from ambulatory electrocardiograms (ECG), and ventricular tachyarrhythmias greater than triplets based on either Holter or ECG monitoring. The serum free triiodothyronine (FT3), free thyroxine (FT4), and reverse triiodothyronine (rT3) levels were measured. Decreased FT3 levels and FT3/FT4 ratios, and increased rT3 levels were associated with worse NYHA class. FT3/FT4 was positively and rT3 was negatively correlated with echocardiographical fractional shortening. FT3 and rT3 were negatively and positively correlated with mean daily heart rates, in contrast to known hypothyroid patients. Patients with ventricular tachycardia demonstrated significantly lower serum values of FT3 and FT3/FT4, and significantly higher values of rT3. Serum thyroid hormone levels can provide a quantitative index for evaluating the severity of chronic heart failure and predicting ventricular tachycardia.

Echocardiography↗
PubMed1993

[Chemo-endocrine therapy with high dose medroxyprogesterone acetate for recurrent or advanced breast cancer].

The endocrine therapy with high-dose medroxyprogesterone acetate (MPA) was applied for 19 patients with recurrent breast cancer and 3 with advanced breast cancer. According to the dominant lesion of the disease, the patients were divided into three groups; 13 with soft tissue lesion, 5 with visceral lesion, and 4 with osseous lesion. The serum MPA level was higher than 25 ng/ml in 14 cases out of 19 examined. The results of objective responses in second-line therapy with MPA were CR in two cases, and NC or PD in 20 cases. In 19 out of 22 patients with MPA therapy, the periods of survival were longer than the period of 50% survival of the patients without MPA therapy.

Adult↗
PubMed1993

[RAEB transformed into AML (M0) showing Ph1 chromosome and rearrangement of major cluster region].

A 78 year old female was found to have pancytopenia in February 1991. Bone marrow was normocellular with 11.7% blasts and showed dysmegakaryopoietic changes. A diagnosis of MDS (RAEB) was made and she was treated with transfusions and ubenimex. Leukemic transformation was noted in July. On Admission in October 1991, her laboratory examinations revealed the following: WBC 38,900/microliters with 93% blast, Hb 8.0 g/dl, Plt 2.1 x 10(4)/microliters, a hypercellular bone marrow with 74% blasts which were negative for myeloperoxidase (MPO) by light microscopy, but were positive by electron microscopy. Surface marker for CD13 was positive. These findings corresponded to M0 of the FAB subtype. Chromosome analysis revealed Ph1 chromosome with 46XX, t (9;22) (q34;q11) in 3 of 3 cells examined, Southern analysis showed the rearrangement of the break point cluster region (bcr). Reverse transcriptase polymerase chain reaction technique demonstrated the presence of major bcr/abl mRNA. She was treated with transfusions and methyl-prednisolone. Her blast counts declined and Ph1 chromosome was only positive in 1 of 12 metaphases examined. She died of pneumonia in December 1991. Eleven cases with MDS showing Ph1 chromosome have previously been reported. The observations indicate that Ph1 chromosome positive acute leukemias were heterogenous in nature.

Aged↗
PubMed1993

Effect of recombinant human erythropoietin administration on immunological indices in patients undergoing chronic hemodialysis.

In patients undergoing chronic hemodialysis, marked anemia may cause decreased immunological function. To improve this anemia, we investigated the effect on immunological indices of recombinant human erythropoietin (rHuEPO) administration in 24 hemodialysis patients (13 males and 11 females) with renal anemia complications. Their mean age was 54.9 +/- 14.8 years and the mean duration of dialysis was 100.5 +/- 54.9 months. The subjects were treated with rHuEPO for 12 months, which helped to maintain a hematocrit value elevated by 5% from the baseline. Cell-mediated immunity and humoral immunity were assessed prior to as well as throughout the treatment period. Of the total number of patients studied, the anemia of 16 improved while 8 did not show signs of sufficient improvement. The improved group showed an increase in in vitro lymphocytic response to phytohemagglutinin (PHA), CD4/CD8, CD16 and serum IgM levels, while the CD8 level decreased significantly. Improvement in the general physical condition with rHuEPO treatment appeared to be associated with the changes in immunological indices, but the precise mechanism remains obscure.

Adult↗
PubMed1993

[A case of surgical treatment of patent ductus arteriosus using left heart bypass in an adult].

This paper describes a new operative method for patent ductus arteriosus using left heart bypass. A 57-year-old woman with patent ductus arteriosus associated with severe pulmonary hypertension was successfully operated upon. Because of aneurysmal dilatation and calcification of the aortic side of the ductus, PDA was divided under left heart bypass with centrifugal pump. Postoperative course was uneventful, and is now well.

Ductus Arteriosus, Patent↗
PubMed1993

Fibronectin expression in cancer tissues from patients undergoing radiation therapy.

Fibronectin expression and distribution were examined in cancer tissues from 19 patients with cancer of the head and neck regions. Samples taken before and after irradiation of approximately 10 Gy, 20 Gy or 30 Gy were analyzed by the avidin-biotin-horseradish peroxidase method using mouse monoclonal antibodies against human fibronectin. The results were correlated with the patient's prognosis after radiation therapy. No remarkable changes in the fibronectin expression or distribution were found between tissue specimens taken before and after each dose of irradiation. The prognosis, however, varied according to the degree of expression and the distribution pattern of fibronectin. Seven patients in which the cancer tissue was encircled by a thick fibronectin network are still alive without recurrence 4.5-6 years after treatment, whereas 6 patients in which fibronectin was only faintly expressed or focally distributed died or developed recurrence soon after treatment. The present findings demonstrate that fibronectin expression and distribution in cancer tissue are intimately related to the patient's prognosis, and that the analysis of these two parameters is applicable as a predictive assay in radiotherapy of cancer of the head and neck regions.

Adult↗
PubMed1993

[Selective cerebral perfusion with cold blood for the aortic arch surgery].

In seventeen patients with aortic arch aneurysms including seven emergency cases, the selective cerebral perfusion with cold blood (16 degrees C) was applied for the cerebral protection during the surgical procedure. Fifteen of them (88%) including the patient with the long cerebral perfusion (236 min) recovered perfectly and discharged. The selective cerebral perfusion with cold blood may be one of the safe and reliable methods for the repair of aortic arch aneurysm.

Adult↗
PubMed1993

[Basic studies of BALL ELSA CA125-II KIT for detection of serum cancer antigen 125].

We made basic studies of BALL ELSA CA125-II KIT which is a solid phase two site immunoradiometric assay. The first monoclonal antibody (M11) is coated on the BALL ELSA solid phase, and the second one (OC125), radiolabeled with 125I, is used as a tracer. Since serum CA125 values varied by incubation time, incubation temperature and agitation speed, the conditions of the assay had to be kept strictly. Intra- and interassay reproducibility, recovery test and dilution test were well satisfied. Prozone phenomenon was observed over 5,000 U/ml. The minimum detectable concentration was 7.5 U/ml. Serum CA125 values measured using BALL ELSA CA125-II KIT was correlated with those measured using conventional CENTOCOR CA125 RIA KIT (y = 1.058x-0.106 r = 0.973), although in the serum of a patient with chronic pancreatitis the discrepancy between serum CA125 values measured using these kits was observed.

Adolescent↗
PubMed1993

[A case of small cell lung cancer associated with diabetes insipidus and Cushing's syndrome].

A 62-year-old male with small cell lung cancer (SCLC) associated with Cushing's syndrome and diabetes insipidus (DI) is reported. The patient was referred to our hospital for treatment of SCLC. A diagnosis of paraneoplastic Cushing's syndrome was made on the basis of an elevated serum ACTH (623.5 pg/ml) level, elevated excretion of urinary 17-OHCS (18.01 mg/day), obesity, hypertension, hyperglycemia, persistent hypokalemia, alkalosis, and no history of diabetes mellitus. He was also diagnosed as having DI based on polyuria and polydipsia, low specific gravity of the urine (1.007-1.010), low serum ADH (1.4 pg/ml) level, normal plasma osmolarity (29 mOsm/kg H2O), and the results of water deprivation test. DI and a left visual field defect was suggestive of metastasis to the pituitary region, but no lesion was detected by either CT scan or MRI scan. The patient failed to show a good response to intensive chemotherapy, and died of the tumor five months after commencing chemotherapy. Post-mortem examination revealed metastases to the hypothalamic-neurohypophyseal region, lungs, liver, adrenal glands, bone, bone marrow, and hilar and mediastinal lymph nodes.

Carcinoma, Small Cell↗
PubMed1993

[A case of small cell bronchogenic carcinoma accompanied by polyneuropathy and SIADH].

A 77-year-old man with small cell lung cancer (SCLC) accompanied by polyneuropathy and SIADH is reported. The patient first developed peripheral hyperesthesia and muscle weakness 6 months before admission. He was diagnosed as having SCLC by sputum cytology and supraclavicular lymph node biopsy. On admission, chest radiography and CT scan revealed a mediastinal mass, and the conduction velocity in peripheral nerves was delayed. He was also found to have SIADH, on the basis of an extremely low level of serum Na (114 mEq/l) and osmotic pressure (251 mOsm/kg) but with normal urinary Na and osmotic pressure. In association with complete disappearance of the mediastinal mass after intensive chemotherapy, SIADH and polyneuropathy also improved remarkably. When SCLC relapsed in the abdominal lymph nodes 11 months after complete disappearance of the mediastinal mass, polyneuropathy and SIADH also reappeared. These results indicate that both SIADH and polyneuropathy comprised a paraneoplastic syndrome.

Aged↗
PubMed1993

Protein kinase C (PKC) activity and PKC messenger RNAs in human pituitary adenomas.

Protein kinase C (PKC) is involved in the differentiation and growth regulation of a variety of tissues including anterior pituitary gland cells. To determine the distribution of PKC in different types of adenomas, PKC activity was analyzed in human pituitary tumors and the effects of hypothalamic hormone stimulation on PKC activity were examined in cultured adenoma cells. Gonadotroph (LH/FSH) and null cell adenomas had significantly higher levels of particulate, soluble, and total PKC activity compared with growth hormone (GH) adenomas (P < 0.05). Chronic stimulation of null cell adenomas with gonadotropin hormone-releasing hormone or of one GH adenoma with GH-releasing hormone for 7 days did not significantly alter total PKC activity in pituitary cells cultured in serum-free medium. Localization of the calcium-dependent PKC isozymes (alpha, beta and gamma) by immunohistochemistry and in situ hybridization revealed predominantly PKC alpha in all adenomas and variable expression of PKC beta and gamma in some tumors. When the calcium-independent PKC isozymes (delta, epsilon, and zeta) were localized by in situ hybridization, normal and neoplastic pituitaries expressed abundant mRNA for PKC epsilon, whereas some tumors and one normal pituitary had a few cells positive for PKC zeta mRNA as evaluated by grain density and the number of cells labeled. These results indicate that there is a variable distribution of PKC mRNA isozymes in human pituitary adenomas and that normal pituitaries and pituitary adenoma cells express the mRNA for both the calcium-dependent and some of the calcium-independent PKC isozymes. Chronic treatment with the hypothalamic gonadotropin hormone-releasing hormone and GH-releasing hormone, which increased LH/FSH and GH secretion, respectively, did not increase PKC activity in cultured adenoma cells. The presence of calcium-dependent and calcium-independent PKC isozymes in normal and neoplastic pituitary cells indicates that PKC probably plays a major role in signal transduction in the human pituitary adenomas examined in this study.

Adenoma↗
PubMed1993

Direct evidence for clonal destruction of allo-reactive T cells in the mice treated with cyclophosphamide after allo-priming.

It has previously been reported that a single i.p. injection of 200 mg/kg cyclophosphamide (CP) 2 days after priming with 10(8) donor spleen cells (SC) leads to donor-specific skin allograft tolerance in H-2 compatible, multiminor antigen incompatible murine strain combinations. It is speculated that the i.v. injection of donor cells may result in synchronized proliferation of donor-reactive host T cells and subsequently administered CP may specifically destroy these proliferating T cells in the periphery. Although this unique action of CP is considered to be a principal mechanism in this method, direct evidence has not yet been obtained. In the present article, this in vivo destructive effect of CP is clearly demonstrated by assessing detailed kinetics of host-derived blastoid T cells and donor (Mls-1a)-reactive V beta 6+ T cells in the model system of C3H mice rendered tolerant to AKR. Frequencies of the blastoid cells and V beta 6+ cells, which increased as a result of AKR priming, decreased rapidly with the administration of CP. C3H mice, which received AKR SC alone, also exhibited partial deletion of V beta 6+ T cells, but both tempo and magnitude of decrease in the frequency of V beta 6+ cells were quite different from those of the C3H mice given AKR SC and CP, which showed more rapid and profound elimination of V beta 6+ T cells. In accordance with these kinetic studies, in vitro proliferative response to Mls-1a antigens was greatly impaired in mice treated with SC and CP, whereas a low but appreciable response was detected in mice given SC alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Protein kinase C activity and messenger RNA modulation by estrogen in normal and neoplastic rat pituitary tissue.

BACKGROUND: Estrogens stimulate pituitary cell growth by prolactin cell hyperplasia in normal rat pituitaries while inhibiting growth of transplantable rat pituitary tumors in vivo and in vitro. The mechanisms by which estrogens stimulate proliferation of normal and hyperplastic pituitary tissues while inhibiting growth of established transplantable tumors is unknown. Protein kinase C (PKC) is involved in proliferation and differentiation of many cells including those of the anterior pituitary gland. PKC has a major role in regulating pituitary hormone synthesis and secretion. Analysis of PKC activity in normal, hyperplastic and transplantable pituitary tumors may provide insight into the mechanism of estrogen action on tumor growth and differentiation in pituitary tissues. EXPERIMENTAL DESIGN: Normal female rats and female rats with transplantable pituitary tumors were treated with estradiol 17 beta (E2) in vivo and subsequently analyzed for PKC activity. Rats with GH3 pituitary tumors were treated with E2 in vivo and a GH3 pituitary cell line maintained in vitro were also analyzed for PKC activity after estrogen treatment. The calcium-dependent and calcium-independent PKC isozymes were analyzed by in situ and Northern hybridization in normal and neoplastic pituitary tissue using specific oligonucleotide probes to characterize the subtypes of PKCs present in pituitary tissues. The calcium-dependent PKCs were also analyzed by immunohistochemistry using specific antibodies to PKC alpha, beta and gamma. RESULTS: Estrogen treatment increased total PKC activity significantly in normal pituitaries, but did not change total PKC activity in transplantable MtT/F4 and MtT/W15 tumors or in GH3 cells in vivo or in vitro. The mRNAs for PKC alpha and beta were detected in normal and neoplastic pituitary tissues and were increased after estrogen treatment in normal pituitary and MtT/F4 tumors, but not in MtT/W15 tumors. The calcium-independent PKC delta, epsilon and zeta were also detected in normal pituitary and in transplantable pituitary tumors and in GH3 cells by Northern hydridization and the levels of these PKCs were also regulated by estrogens. CONCLUSIONS: Estrogen modulates PKC levels in pituitary cells with an increase in total PKC activity in hyperplastic pituitaries but not in transplantable pituitary tumors. Estrogen also regulates the mRNA levels of the calcium-dependent and calcium-independent PKC isozymes.

Animals↗
PubMed1992

Butyrylcholinesterase-rich neurons in rat brain demonstrated by a sensitive histochemical method.

Butyrylcholinesterase (BChE) is a highly active enzyme in brain, but little is known about its physiological functions. One obstacle has been the lack of a sensitive and specific method for determining its cellular localization. We report here on a histochemical technique that has permitted BChE to be detected in neuronal, glial, and vascular structures. The method, which utilizes butyrylthiocholine iodide as the substrate, is a modification of our previously described method for acetylcholinesterase (AChE) histochemistry. BChE-rich neuronal somata stained much more intensely than capillaries or glia. Prominent neuronal groups were located in the anterodorsal, laterodorsal, anteroventral, reuniens, centrolateral, paratenial, and periventricular thalamic nuclei, the laterodorsal tegmental nucleus, the pedunculopontine tegmental nucleus, and the dorsal motor nucleus of vagus. Several other areas of the forebrain and brainstem showed modest numbers of positive cells. No positive cells were detected in the striatum, hippocampus, and most parts of the hypothalamus, which are regions containing numerous AChE-rich neurons. Although the distribution pattern of BChE-rich neurons differed from that of AChE-rich neurons, some neuronal groups contained both esterases. The results suggest that BChE may play a unique role in neuronal function, particularly since many BChE-rich neurons have not been identified as to neurotransmitter type.

Acetylcholinesterase↗
PubMed1992

Interference with cyclophosphamide-induced skin allograft tolerance by cyclosporin A.

In a murine strain combination identical in H-2 Ag but disparate in minor histocompatibility (H) Ag consisting of C3H/He (C3H; H-2k, Mls-1b) mice as recipients and AKR/J (AKR; H-2k, Mls-1a) mice as donors, a permanent skin allograft tolerance can be achieved by the cyclophosphamide (CP)-induced tolerance system that consists of i.v. injection of donor spleen cells (day -2) and i.p. injection of CP 2 days later (day 0). Such permanent take of allografts in CP-induced tolerant mice was interfered with by intramuscular injection of cyclosporin A (CsA) from day -5 to day -1 and their grafts were rejected by 21 days after grafting. Mls-1a-reactive CD4+V beta 6+ T cells in the periphery, as the indicator to follow the kinetics of donor-reactive T cells, increased on day 0 and day 3 in the C3H mice treated with AKR spleen cells alone, whereas they disappeared rapidly from day 0 to day 3 in CP-induced tolerant mice. When CsA capable of interfering with IL-2 production and T cell proliferation was administered before CP treatment in CP-induced tolerance system, the number of CD4+V beta 6+ T cells in periphery did not increase on day 0 and 3, but increased on day 7 in contrast to the decreased number of those in CP-induced tolerant mice. On day 7, MLR against donor cells was decreased in CP-induced tolerant mice, but maintained in CsA-interfered tolerant mice. These result may indicate that the destruction of donor-Ag-stimulated, proliferating T cells by CP is interfered with by CsA, probably because CsA inhibits the proliferation of donor-reactive T cells at the time of CP treatment. Furthermore, these results also implicate that the protocol for immunosuppression with CsA and antimetabolites has to be designed carefully in clinical transplantation.

Animals↗