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Biomedical subjects

A Sakai

Publications and source records attributed to A Sakai.

At least 289 records · Page 16Linked to original sources
PubMed1990

[Sudden deaths among male employees: a six-year epidemiological survey].

To elucidate the circumstances involving sudden death, deaths among 20,685 male employees of "K" company during a six-year period from April 1981 to March 1987 were reviewed. The subject age ranged from 19 through 59 years, and averaged 38.6 years. Information concerning each death was obtained from the death reports prepared by officials of the Safety and Health Division of the Labor Affairs Department of this company, based on the death certificate and interviews with questionnaires to the deceased's family, colleagues, and attending physicians. In this study, "sudden death" was defined as the death of a full-time employee who had been capable of performing ordinary work and who died within 24 hours after the onset of a sudden disease. When the cause of death could not be determined, the cause was categorized as unknown. A total of 233 employees died during the six-year period. The causes were malignant tumors in 107 (45.9%), heart diseases (including all of the sudden deaths from "unknown cause") in 41 (17.6%), cerebral vascular accidents in 20 (8.6%) and other causes in 64. "Sudden death" occurred in 39 employees. This accounted for 12 to 33% (17% average) of the total deaths. The mortality of sudden death by age group (adjusted to the annual deaths per 100,000 persons) was six in the age of 30-34 years, 20 for 35-39 years, 22 for 40-44 years, 54 for 45-49 years, 51 for 50-54 years and 107 for 55-59 years, an average of 33. In seven sudden death cases, the last medical examinations before death indicated "no abnormalities".(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Endocrinological analysis of climacteric symptoms and gonadal dysfunction by CRF test].

Endocrinological studies on stressed climacteric women and some cases of gonadal dysfunction were carried out by analysing blood levels of adrenocorticotropic hormone (ACTH), beta-lipotropin (beta-LPH) and beta-endorphin (beta-EP) after the administration of synthetic corticotropin releasing factor (CRF, CRF test). Our results can be summarized as follows: 1. The responsiveness to CRF in perimenopausal and ovariectomized women rose and it corresponded with those of post gonadectomy in testicular feminization. 2. Responsiveness to CRF was decreased as estrogen levels decreased with the patient's age, and a similar tendency was observed in gonadal dysfunction. 3. Climacteric women with non-specific complaints have a higher responsiveness to CRF than that of postmenopausal women without complaints. Subjects with a high K.I score and with severe hot flush showed higher responsiveness to CRF than other subjects. These data suggest that CRF and its related hormones may be correlative with stress and hot flushes in climacteric periods and endogenous CRF may play an important psychosomatic role by regulating the hypothalamo-pituitary-adrenal function where there is decreased estrogen.

Adrenocorticotropic Hormone↗
PubMed1990

[General pharmacology of BMY-28100].

General pharmacological properties of BMY-28100, a new semisynthetic oral cephalosporin, were studied in experimental animals. The obtained results are summarized as follows: 1. BMY-28100 had no effect on gross behavior and the central nervous system in mice and rats nor on EEG activities in rabbits. 2. BMY-28100 did not affect the smooth muscle isolated from rats, guinea pigs or rabbits nor did it influence ganglionic transmission in cats. 3. Effects of BMY-28100 on the atrium and heart isolated from guinea pigs were not obvious. Several parameters of the cardiovascular system were examined and found unchanged by administration of BMY-28100 to rabbits. 4. In the digestive system, BMY-28100 had no effect on charcoal meal transport in the small intestine of mice. In rats, however, gastric secretion was reduced at a dose level of 125 mg/kg or higher and bile secretion was enhanced at a dose level of 500 mg/kg. 5. BMY-28100 had no effect on neuromuscular transmission in rabbits and showed no local anesthetic activity in guinea pigs. 6. BMY-28100 decreased urine volume and urinary excretion of electrolytes in dose-dependent manners in rats. Sulfobromophthalein excretion in rats was inhibited only at the highest dose tested. BMY-28100 had no effect on blood coagulation and red blood cell resistance in rats or rabbits. BMY-28100 revealed no antiinflammatory activity in rats. 7. BMY-28167, a trans-isomer of BMY-28100, had no or weak effects on some of above test systems when compared with BMY-28100. These results suggest that BMY-28100 has hardly any pharmacological properties leading to severe adverse reactions in clinical use.

Administration, Oral↗
PubMed1989

Molecular characteristics and physical state of human papillomavirus DNA change with progressing malignancy: studies in a patient with epidermodysplasia verruciformis.

In order to establish the role of human papillomavirus (HPV) in carcinogenesis of epidermodysplasia verruciformis (EV), the presence, the molecular characteristics and the physical state of HPV DNA in a benign lesion, a primary carcinoma and a metastatic carcinoma developing in the same EV patient were studied and compared. Of the 2 HPV DNAs isolated from benign macular lesions, only one (a subtype of HPV 5) was detected in both primary and metastatic tumors. Only one normal species of viral DNA molecule was detected in the benign lesion, whereas most, if not all, viral DNA molecules present in the carcinoma (both primary and metastatic) were aberrant ones. The major viral DNA molecule in the primary carcinoma was a large HPV DNA with duplicated 40% subgenomic segments, and was present as free episomes. The major viral DNA molecule in the metastatic carcinoma was the 40% subgenomic segment itself, lacking the remaining 60% segment of the viral genome, and was integrated within cellular DNA. Thus, HPV DNA was present in tumors at any stage of malignancy, and its molecular characteristics and physical state changed not only with the development but also with the enhancement of malignancy, consistently conserving its defined 40% subgenomic segment as the predominant viral sequences. Our results suggest that HPV 5 may be actually involved in carcinogenesis in EV patients.

Carcinoma, Squamous Cell↗
PubMed1989

Neurons of origin of the internal ramus of the rabbit accessory nerve: localization in the dorsal nucleus of the vagus nerve and the nucleus retroambigualis.

The neurons of origin of the internal ramus of the rabbit accessory nerve were identified in the dorsal nucleus of the vagus nerve, using bilateral injections of horseradish peroxidase into the inferior vagal ganglion, soft palate, and pharynx, which were preceded by different combinations of the unilateral intracranial severings of the rootlets of the vagus and glossopharyngeal nerves, those of the cranial root of the accessory nerve, and the trunk of its spinal root. The neurons of origin occupied the caudal four-fifths of the dorsal vagal nucleus extending from about 1.0 mm rostral to the obex as far caudally as the second cervical spinal segment, with their number being about half the total number of neurons of the nucleus. Although considerably fewer, they were also located in the nucleus retroambigualis of the caudal half of the first cervical spinal segment and the second segment. Axons of most internal ramus neurons traversed the rootlets of the cranial accessory root. Axons of the few neurons located more caudally than about 1.0 mm caudal to the obex emerged from the upper cervical spinal cord to run along the trunk of the spinal accessory root before finally joining the internal ramus; caudal to the midlevel of the first cervical segment, the dorsal vagal nucleus and the nucleus retroambigualis contained neurons whose axons followed only that course.

Accessory Nerve↗
PubMed1989

Isolation and characterization of Escherichia coli hag operator mutants whose hag48 expression has become repressible by a Salmonella H1 repressor.

The expression of an Escherichia coli K12 flagellin gene, hagA48, is insensitive to the Salmonella H1 repressor (rh1+). By selecting merodiploid cells H2-rh1on-off/F'hag48 for motility in the presence of anti-H48 serum, mutants which had escaped from inhibition by the serum because of repression of their hag48 expression by rh1+ were isolated. Their nucleotide sequences were examined in the region containing the promoter, the position of which was confirmed by S1 nuclease analysis of the transcriptional initiation site. The two independently isolated mutants had the same heptamer insertion AGACGAT at a site overlapping with the promoter sequence, creating a putative operator sequence homologous to Salmonella H1, but not to H2. Other candidates for operator mutants had reduced flagellar synthesis because of mutations between the transcriptional and translational initiation sites or in the structural gene. The sequence analysis also revealed a repetitive extragenic palindrome (REP) consensus sequence and a transcriptional terminator of hag48 in a small, functionally unknown open reading frame (ORF).

Amino Acid Sequence↗
PubMed1989

Improvement of carcinogen identification in BALB/3T3 cell transformation by application of a 2-stage method.

The present studies intend to heighten the sensitivity of BALB/3T3 cells to chemical carcinogens in a transformation assay, by including exposure of carcinogen-treated cells to a tumor promoter, 12-O-tetradecanoylphorbol 13-acetate (TPA). In the assay, cells were first treated with a known or suspected carcinogen for 72 h, cultured in normal medium for 3 days, exposed to media with and without TPA for 2 weeks, and cultured in normal medium for an additional 3 weeks. Benzo[a]pyrene, a potent carcinogen with a polycyclic aromatic hydrocarbon structure, caused transformation in the presence and absence of TPA. N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG), a carcinogen with direct-acting alkylating ability, did not induce significant transformation without TPA, while treatment with MNNG followed by TPA produced numerous transformed foci, classifying MNNG as an initiating agent of transformation under the condition presented in this report. 3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2), sodium nitrite and butylated hydroxyanisole (BHA), which are carcinogenic and/or mutagenic, produced transformed foci in significant numbers of treated dishes in the presence but not in the absence of TPA. Butylated hydroxytoluene (BHT) and sodium saccharin, which are considered to be a modifier and a promoter of carcinogenesis, did not cause significant transformation with or without TPA treatment. These studies suggest that this 2-stage transformation system is capable of detecting a wider range of chemical carcinogens as initiating agents than the standard assay. Studies on the transformation assay schedule revealed that the proportion of dishes with foci, the number of foci per dish and sizes of foci all increased in the normal medium after the termination of TPA treatment. Therefore, transformed cells appear to proliferate independently of TPA after those cells are released by TPA from postconfluence inhibition of cell division.

Animals↗
PubMed1989

Clinical validation of St. Thomas' Hospital cardioplegic solution No. 2 (Plegisol).

Recently, the St. Thomas' Hospital cardioplegic solution No. 2 (Plegisol) has become available commercially in the UK. In a series of patients (n = 28) undergoing open heart surgery for a variety of lesions, a clinical validation was performed. Preservation of myocardial contractility was assessed biophysically by quantitative birefringence measurements of myocardial biopsy samples (full thickness apical left ventricle and right ventricle) taken (1) prior to ischaemia, (2) at the end of ischaemia and (3) 10-15 min after reperfusion during cardiopulmonary bypass. In addition, serum CK-MB values were measured in samples taken throughout the operation and for 4 days postoperatively. Postoperative ECG traces (taken every 6 h for 48 h and then daily up to 7 days) were analysed to identify the occurrence of perioperative infarction. There were no hospital deaths. Chronotropic support was required in 5 of 28 patients (18%) for transient heart block. Low cardiac output did not occur postoperatively. Birefringence measurements in biopsy samples taken at the end of the ischaemic period (immediately prior to reperfusion) indicated an apparent left ventricular deterioration in myocardial contractility in 12 of 28 patients (43%) when compared to biopsies sampled prior to the ischaemic period. However, after 10-15 min of aerobic reperfusion, measurements indicated that myocardial contractility recovered to almost pre-ischaemic levels in the majority of patients. Thus, in 22 of 28 patients (79%), left ventricular deterioration did not occur in post-ischaemic biopsy samples when compared to the pre-ischaemic biopsies. Similarly, 21 of 28 patients (75%) had no deterioration of birefringence values in right ventricular biopsies.(ABSTRACT TRUNCATED AT 250 WORDS)

Bicarbonates↗
PubMed1989

Human chorionic gonadotropin-ricin A chain hybrid protein: a hormone analog for the study of signal transduction.

We have prepared a disulfide cross-linked hybrid consisting of human chorionic gonadotropin and the toxic ricin A chain, utilizing N-succinimidyl-3-(2-pyridyldithio)-propionate. The purified hybrid exhibited cytotoxicity toward rat testis Leydig cells due to inhibition of protein synthesis within the cells, although it inhibited protein synthesis in a cell-free system of a rabbit reticulocyte lysate only after treatment of the hCG-A hybrid with dithiothreitol. On the other hand, pretreatment of the hCG-A hybrid with dithiothreitol completely abolished its cytotoxicity. The hCG-A hybrid stimulated the testosterone production by rat testis Leydig cells to a similar degree to hCG. The hCG-A hybrid could elicit full testosterone production in the presence of about 1/3-1/2 less accumulated cAMP compared with in the case of hCG stimulation. The steroidogenetic effect of the hCG-A hybrid was largely inhibited by anti-hCG antibody but not by anti-ricin A chain antibody. These results suggest that the hCG-A hybrid first binds to Leydig cells via an hCG receptor and then is internalized into the cells, and finally the inhibition of cellular protein synthesis occurs on the release of the ricin A chain from the hybrid. Furthermore, it was suggested that hCG may stimulate testosterone production via another second messenger system as well as via the cAMP system, since the hCG-A hybrid stimulated full testosterone production without maximal cAMP accumulation.

Animals↗
PubMed1989

Importance of vasoconstriction in lipid mediator-induced pulmonary edema.

Lipid mediators of inflammation cause pulmonary edema, yet it is unclear to what degree hemodynamic alterations or increased vascular permeability contribute to lung edema formation. The isolated rat lung preparation was used to examine the effect of leukotriene C4 (LTC4) and platelet-activating factor (PAF) on pulmonary arterial pressure (Ppa), lung microvascular pressure (Pmv), lung wet-to-dry weight ratio, and the 125I-albumin escape index. We first defined the response of the isolated rat lung perfused with protein-free salt solution to hydrodynamic stress by raising the lung outflow pressure. Sustained elevation of the lung outflow pressure less than 5.5 cmH2O (4.01 mmHg) caused a negligible increase in Ppa and wet-to-dry lung weight ratio. Elevation of outflow pressures greater than 7.5 cmH2O (5.4 mmHg) increased the vascular albumin escape index more than the lung wet-to-dry weight ratio. Dibutyryl adenosine 3',5'-cyclic monophosphate (db-cAMP) inhibited the increase in albumin escape index because of increased lung outflow pressure, suggesting perhaps a pressure-independent microvascular membrane effect of db-cAMP. Both LTC4 (2-micrograms bolus) and PAF (2-2,000 ng/ml perfusate) increased the albumin escape index in association with increases in Ppa and Pmv. Because the increased albumin escape index after LTC4 or PAF injection was largely accounted for by the increased vascular pressures and because db-cAMP and papaverine inhibited the rise in vascular pressures and in the albumin escape index, we conclude that vasoconstriction is an important contributor to LTC4- and PAF-induced edema formation in rat lungs.

Animals↗
PubMed1989

Dibutyryl-cAMP blocks endotoxin-induced lung injury in rats.

We investigated the effect of dibutyryl-cAMP pretreatment on endotoxin-induced hemodynamic changes and lung vascular injury in rats. In catheter-implanted, unanesthetized rats, intraperitoneal injection of Salmonella enteritidis endotoxin (2 mg/kg) decreased cardiac output and systemic blood pressure while increasing total pulmonary vascular resistance. Db-cAMP (1 mg given intraperitoneally every 30 min), although not significantly affecting cardiac output and systemic blood pressure, blocked the increase in total pulmonary resistance caused by endotoxin. Ninety minutes after intraperitoneal endotoxin injection, perfused lungs from endotoxin-treated rats exhibited increased pulmonary vascular permeability, as assessed by increased extravascular accumulation of 125I-albumin and water. Db-cAMP treatment in vivo markedly attenuated the increases in lung albumin leak index and wet-to-dry weight ratio caused by endotoxin without affecting lung microvascular pressures. This protective action of db-cAMP is not due to its effect on prostaglandin or leukotriene synthesis since endotoxin-stimulated increases in lung tissue 6-keto-prostaglandin F1 alpha, thromboxane B2 and leukotriene C4 were not inhibited. We conclude that db-cAMP blocks endotoxin-induced lung injury in the rat by a mechanism independent of eicosanoid products and speculate that agents that increase intracellular cAMP may be therapeutically useful in acute lung vascular injury.

Albumins↗
PubMed1989

Effect of TRK-100, a prostacyclin analogue, on endotoxin-induced enhancement of blood coagulation in rats.

TRK-100 (0.03, 0.1 and 0.3 mg/kg, p.o.), a chemically stable analogue of prostacyclin, dose-dependently prevented blood coagulation and glomerular fibrin deposition which were enhanced by 4 hr infusion of endotoxin (100 mg/kg) in rats. In addition, TRK-100 suppressed the generation of endotoxin-induced tissue thromboplastin like activity in cultured human endothelial cells.

Administration, Oral↗
PubMed1989

Climatic adaptation in thermogenesis and thermal insulation in wood mice (Apodemus argenteus).

Wood mice (Apodemus argenteus) were trapped live at three different altitudes (below 1,000, 1,900, and 2,400 m) during a 1-year period (Feb. 1984-Jan. 1985). After remaining at the trapped locations for 10-14 days, they were transferred into a climatic chamber at an altitude of 610 m. Oxygen consumption (VO2) and colonic temperature (Tco) were measured at chamber temperatures (Ta) of five steps (30, 20, 10, 0, and -10 degrees C) in freely moving conditions. In response to Ta of 0 degrees C for the mice trapped in winter when their mean local habitat temperature (Te) were lower than 0 degrees C, there was a significant inverse correlation between VO2 and Te (r = -0.70, p less than 0.001) whereas no significant correlation (r = 0.23) was observed in the mice trapped in other seasons when Te was higher than 0 degrees C. The correlation between Tco and Te was significant (r = -0.66, p less than 0.001) over the entire range of Te. The pelt weight of the mice trapped at Te higher than 0 degrees C had a significant inverse correlation with Te (r = -0.65, p less than 0.001), but not in the mice trapped at Te lower than 0 degrees C. After measurement of VO2 and Tco at Ta of 0 degrees C, the mice who had lived in colder habitats (below 0 degrees C) showed 0% mortality, whereas the mortality of the populations which had lived in warmer habitats was 13%. These results suggest that, in wood mice, adaptation to severe cold is established by an enhanced thermogenesis and by an increased insulation of the pelt in moderate cold.

Adaptation, Physiological↗
PubMed1989

Effect of beraprost sodium on peripheral circulation insufficiency in rats and rabbits.

Beraprost sodium (sodium (+/-)-(1R*,2R*,3aS*,8bS*)-2,3,3a,8b-tetrahydro-2- hydroxy-1-[(E)-(3S*)-3-hydroxy-4-methyl-1-octen-6-ynyl]-1H- cyclopenta[b]benzofuran-5-butyrate, TRK-100) is a chemically and biologically stable epoprostenol analogue which possesses both potent antiplatelet and peripheral vasodilating actions. Its effect on obstruction of the peripheral artery was studied in three different models: 1. acute thrombosis induced by electrical-stimulation of the femoral artery in rabbits, 2. occlusion induced by intra-arterial injection of sodium laurate in rats and 3. tail gangrene induced by subcutaneous injections of both ergotamine and epinephrine in rats. Oral administration of beraprost sodium resulted in suppression of thrombus formation in the acute thrombosis model, marked improvement of macroscopic and histological observations in the laurate-occlusion model and inhibition of tail gangrene extension. In contrast, ticlopidine improved thrombus formation in the acute thrombosis model and slightly improved histological observation in the laurate-occlusion model, but not in the tail gangrene model. Cilostazol suppressed lesions in the acute thrombosis model, but not in the tail gangrene model. These findings suggest that beraprost sodium may be very useful clinically for the therapy of peripheral circulation insufficiency diseases such as Buerger's disease and Raynaud's disease.

Acute Disease↗
PubMed1989

[The importance of aortic compliance as a prognostic factor after aortic valve replacement].

A variety of clinical variables and physiological parameters have been discussed in relation to postoperative survival and symptoms in aortic regurgitation (AR). Many of them have been derived from left ventricular morphology and functions, but there has been no parameter from aortic functions. As the heart is united with the aortic tree to form a circulatory system and both heart and aorta affect each other, aortic functions also have an important prognostic value after aortic valve replacement (AVR). This study was performed to clarify the participation of aortic functions in determining the prognosis after AVR. Fifteen consecutive patients undergoing isolated AVR for AR were evaluated. Twenty-one preoperative hemodynamic and dimensional variables of both heart and aorta were analyzed to determine the risk factors for early postoperative morbidity. These variables were obtained from chest X-ray film, electrocardiogram, echocardiogram, cine-aorto-ventriculogram and pressure manometries. All patients were divided in two groups according to the postoperative course. Group I composed of 10 patients took relatively smooth postoperative course, except two patients suffering from cardiac tamponade. Group II composed of 5 patients suffered from low cardiac output syndrome (LOS) and/or dangerous arrhythmias postoperatively. Two out of them died of uncontrollable ventricular arrhythmias. There were no statistic differences between two groups in the factors derived from preoperative examinations, i.e. CTR, LVDsI, PWT, R/Th, %FS, EDVI, EF, CI, LVEDP, etc. Mean aortic compliance of group II, (3.8 +/- 2.1) X 10(-4) mmHg-1, was, however, significantly lower than that of group I, (21.7 +/- 4.8) X 10(-4) mmHg-1, (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[The deformed partially edentulous ridge in the area of the anterior teeth and that reconstruction. Part I. Analysis of types of defects by the study casts].

The purpose of the study was investigated the incidence and type of anterior ridge deformities in partially edentulous patients. Furthermore that deformed partially edentulous ridge were investigated which esthetic problem were existence or not, and what type of edentulous ridge have to do the ridge augmentation. A random sample of 94 casts 118 regions was evaluated. The results obtained were as follow: 1. These partially edentulous ridge were measured distance by the divided into Apicocoronal loss D1 and Buccolingal loss W, and relationship between D1 and W was significant. But the relationships of D1 and W weren't found between 1 to 2 missing tooth, and on the presence of the root exposure. 2. The resorption form at the palatal regions of upper differed from lower, remained to alveolar crest on palatal regions. But the resorption form at the Buccal region were similar to upper and lower. 3. Using Seibert's classification, we found that the Class III was the most prevalent deformity (55.1%). The other prevalent defect was discerned the Class 0 (17.8%) greater than Class I (16.1%) greater than Class II (11.0%). 4. An unesthetic pontic-to-ridge relationship observed in an Apicocornal loss or a Buccolingal loss. 5. The surgical procedures for reconstruction to partially edentulous ridges should be carried out the either D1: greater than 3 mm or W: greater than 3 mm. The edentulous ridges which lacked in the either D1: greater than 2 mm or W: greater than 2 mm were considered preparatory application.

Alveolar Process↗
PubMed1989

[Surgical experience with an infant with discrete subaortic stenosis successfully treated by aortoventriculoplasty].

A 3-year-old female with discrete subaortic stenosis is presented. Angiocardiographic studies showed a long segmental narrowing below the aortic valve. Although membranectomy and myectomy were selected as a surgical treatment, a longitudinal aortotomy was performed in order to extend the operation to ventriculoseptoplasty. During the operation, the right coronary cusp was seriously damaged and therefore aortoventriculoplasty was applied. The aortic valve was replaced with a 21 mm St. Jude Medical mechanical prosthesis. The left ventricular outflow tract was adequately enlarged, and postoperative course was uneventful.

Aorta↗