Biomedical subjects

A Kohyama

Publications and source records attributed to A Kohyama.

At least 19 recordsLinked to original sources

PubMed2001

A sensitive method for detecting Porphyromonas gingivalis by polymerase chain reaction and its possible clinical application.

BACKGROUND: It is useful for the clinical diagnosis of periodontitis to monitor the colonization of periodontopathic bacteria in periodontal pockets. In this study, we attempted to establish and possibly identify the clinical application of a sensitive method to detect Porphyromonas gingivalis (P.g.), one of the putative periodontopathic bacteria related to chronic periodontitis. METHODS: Genomic DNA extracted from cultured P.g. 381 and clinically isolated subgingival plaque samples were used as a template of polymerase chain reaction (PCR). We designed primers to amplify the genomic DNA coding 40 kDa outer membrane protein (OMP), one of the unique proteins to all strains of P.g. The efficiency and specificity of amplification were evaluated by agarose gel electrophoresis and subsequent Southern hybridization with a digoxygenin-labeled oligonucleotide probe. RESULTS: Fewer than 100 P.g. bacterial cells in the specimen were reproducibly detected by PCR-hybridization assay. This PCR-hybridization assay was at least 100 times more sensitive than the conventional indirect immunofluorescence assay (IIF). Furthermore, the imaging analysis showed that there is a linear correlation between the strength of the signal and the cell number of P.g. from which the template DNA was extracted semiquantitatively. It is noteworthy that the PCR assay could also be applied to detect P.g. from clinical plaque samples and that it was approximately 100 times more sensitive than a conventional IIF assay. CONCLUSION: The PCR assay established in this study can be a powerful tool to detect P.g. in periodontal pockets and monitor the colonization and/or recolonization of P.g. at the very early phase.

Bacterial Outer Membrane Proteins↗

PubMed2000

[Severe lightning pain during spinal anesthesia in a patient with diabetic neuropathy].

A 71-year-old woman with diabetic neuropathy who had undergone amputation of the right lower leg for diabetic gangrene 4 years previously, experienced severe lightning pain in both legs during spinal anesthesia. She was scheduled for skin grafting for a burn ulcer on her left foot. Her preoperative physical examination revealed hypesthesia in both legs due to diabetic neuropathy. Spinal anesthesia was performed with a combined spinal-epidural needle at the L 4-5 interspace using 2.0 ml of 0.3% hyperbaric dibucaine in the left lateral position. The region of hypesthesia was spread below Th 4. Ten minutes later, she complained of severe lightning pain in both legs and midazolam 1 mg was administered intravenously against agitation. The severe lightning pain diminished after the administration of pentazocine 7.5 mg intravenously in the recovery room. There was no worsening of neurological findings 5 hours later when the effect of spinal anesthesia disappeared. This clinical picture seems to be different from that of reported cases of phantom limb pain during spinal anesthesia in which severe lightning pain occurred in both legs. This case suggests that patients with diabetic neuropathy might develop severe lightning pain during spinal anesthesia using dibucaine.

Aged↗

PubMed1998

[Intra-arterial infusion chemotherapy for advanced endometrial cancer before surgical treatment].

Nine cases of advanced uterine body cancer (stage III: 8, stage IVa: 1) were treated by intra-arterial infusion chemotherapy before curative operation. This treatment produced primary tumors smaller than half sizes in eight cases. Necrotic changes were found in over two-thirds of the lesions in six cases. This chemotherapy enabled us to operate curatively in seven cases. After the operations, we performed various types of treatment including intra-arterial infusion chemotherapy. No evidences of disease have been found in four cases, but there is no significant difference between the groups receiving and not receiving the intra-arterial infusion chemotherapy (n = 16) in terms of survival rate of stage III. Further study of the prognosis is necessary.

Adenocarcinoma↗

PubMed1997

Immunolocalization of Drosophila eye-specific diacylgylcerol kinase, rdgA, which is essential for the maintenance of the photoreceptor.

The Drosophila retinal degeneration A (rdgA) mutant has photoreceptor cells that degenerate within a week after eclosion. The degeneration starts with the disruption of the subrhabdomeric cisternae (SRC), which are the organelles essential for the transport of phospholipids to the photoreceptive membranes. Our previous biochemical and molecular studies suggested that the rdgA gene encodes an eye-specific diacylglycerol kinase (DGK). In this study, we show that retinal degeneration is prevented by the introduction of the eye-DGK gene in the rdgA mutant genome, suggesting that the DGK activity is crucial for the maintenance of the photoreceptor. Furthermore, by immunohistochemical analysis, we have demonstrated that the rdgA protein is predominantly associated with the SRC, suggesting that the conversion from diacylglycerol (DG) to phosphatidic acid (PA) most actively occurs in SRC. The analysis of the eyes of mutants homozygous for rdgA and eye-protein kinase C mutations indicates that retinal degeneration is caused by the deficiency of PA rather than excessive accumulation of DG. From these data, we conclude that the production of PA in the SRC membranes is essential for the maintenance of the photoreceptor.

Animals↗

PubMed1997

[Epidural fentanyl provide sufficient analgesia for extracorporeal shock wave lithotripsy (ESWL)].

Epidural fentanyl (0.2 mg in 10 ml normal saline) was administrated in 10 unpremedicated patients undergoing extracorporeal shock wave lithotripsy (ESWL). No test dose of local anesthetics was administrated and accessory drugs such as narcotics or analgesics were not used. Painful procedures except for shock wave such as insertion of urethral catheter were not applied. We observed analgesic effect using original score (grade 0-3) and monitored heart rate, blood pressure, respiratory rate and Spo2 during ESWL. At 1, 2, 3, 4 and 24 hours after ESWL, patients were questioned regarding the presence of postoperative nausea, vomiting, and motor disturbance. At the start of ESWL, nine patients experienced mild pain, although no patient requested additional analgesic treatment. Until the end of ESWL, local anesthetics were administered through the epidural catheter in three patients because of increase of pain, while the others completed ESWL with epidural fentanyl alone. No remarkable change in blood pressure and heart rate were observed. Respiratory rate and Spo2 slightly decreased during ESWL. Postoperative side effects were mild especially in the patients treated with epidural fentanyl alone. Epidural fentanyl is considered to be useful analgesic technique for ESWL.

Adult↗

PubMed1997

[Coronary artery bypass grafting on the beating heart in patients with severe cardiac dysfunction; on the necessity of cardiopulmonary bypass].

Six patients with severe cardiac dysfunction due to acute myocardial infarction underwent coronary artery bypass grafting on beating hearts, because we were afraid of difficulty in weaning from the cardiopulmonary bypass (CPB). The first two operations were performed without use of CPB (group A) and the following cases were done with CPB (group B). All patients received emergent operations except one, and three patients needed intra-aortic balloon pumping support perioperatively. Although all patients had three vessel disease, the number of the graft was one or two. Anesthesia was maintained by fentanyl, midazolam, sevoflurane and nitrous oxide. All patients in group B could be weaned from the CPB easily. In a patient of group A, hypotension persisted during cardiac procedure. In a patient of group B, ventricular fibrillation occurred when the coronary artery was occluded by snares. In another patient of group B, we discontinued inotropic agents and used verapamil during CPB for a easy cardiac procedure and myocardial protection. We conclude that coronary artery bypass grafting on the beating heart in the patients with severe cardiac dysfunction due to acute myocardial infarction should be performed with CPB to maintain systemic hemodynamics, to protect myocardium during occlusion of the coronary artery, and to make the surgical procedure easy.

Aged↗

PubMed1997

[Application of Internet technology in public health].

Recent advances in telecommunication technology have been enormous. Application of this technology in public health has the potential to markedly improve global health through better surveillance and information systems. With this assumption the GHNet was established in 1994 by representatives from academia, WHO, Pan American Health Organization, the World Bank, NASA, IBM, and AT & T. The GHNet consists of seven components: 1) promotion of networking with the Internet among people in public health; 2) disease tele-monitoring; 3) distance learning system with the internet; 4) connection of non-governmental health organizations; 5) training cyberdocs who are educated in both public health and telecommunications; 6) establishment of an electronic scientific research server; and 7) a home page on the World Wide Web (WWW). In order to effectively incorporate the Internet into the field, connectivity and knowing how to use it are of critical concern. More and more facilities are connected to the Internet in Japan. However, few courses teaching how to utilize the Internet are provided for people in this field. An Internet training course for people in public health was held as joint venture of the World Health Organization (WHO) and the Global Health Network (GHNet) on October 31, 1996, at the 55th Annual Meeting of Japanese Society of Public Health. Most of the participants for the course were from local public health departments and very few had previous experience with the Internet before the course. During this course participants learned how to use e-mail, how to find health resources on the WWW, how to construct a home page, and how the Internet could be utilized to improve public health, with their computers actually hooked to the Internet. From this experience, we found that this kind of course is feasible and beneficial and hope that this course would serve as a model for training people in public health.

Computer Communication Networks↗

PubMed1996

[Isoflurane and sevoflurane impair left ventricular relaxation in dogs with fixed heart rate].

The effects of isoflurane (Iso) and sevoflurane (Sev) on left ventricular relaxation were evaluated in 22 open-chest dogs with fixed heart rate (130 beats.min-1) using atrial pacing. Fentanyl was injected intravenously to maintain anesthesia during the preliminary preparation. In both Iso and Sev groups (n = 11), left ventricular systolic pressure, mean aortic pressure and dp/dt max were significantly decreased at 0.5 MAC, but there was no significant change in left ventricular end-diastolic pressure. Left ventricular systolic function was depressed to the similar extent in both groups. In Sev group, -dp/dt max and time constant of isovolumic left ventricular pressure fall (T) increased significantly at 0.5 MAC but it increased at 1.5 MAC in Iso group. T at 0.5 MAC Sev was also significantly longer compared with T at equipotent Iso. These findings suggest that Sev may impair isovolumic left ventricular relaxation more strongly than Iso, and this may result from the difference of the effect of each agent on intracellular Ca2+ homeostasis in the myocardium.

Anesthetics, Inhalation↗

PubMed1996

[Blood coagulation-fibrinolysis system during transurethral resection evaluated by thrombelastography].

Intraoperative changes in blood coagulation-fibrinolysis system were evaluated in 21 patients under epidural anesthesia by thrombelastography. Ten patients received transurethral resection of prostate (TUR-P) and 11 patients received transurethral resection of bladder tumor (TUR-Bt). Thrombelastographic variables: reaction time (R), coagulation time (K), maximum amplitude (MA), and amplitude 60 min after MA (A 60) were measured. The coagulability was evaluated by R + K, the absolute strength of clot by MA, and fibrinolysis using MA-A60. There was no significant change of these indices in TUR-Bt group. On the other hand, in TUR-P group, R + K was significantly shortened and MA-A60 had a tendency to increase it, but MA caused no change. Resected prostatic weight correlated significantly with the decrease of MA, and had a tendency to correlate with the increase of MA-A60 in TUR-P group. Both coagulation and fibrinolysis were activated in TUR-P group. When the resected prostatic weight is large, the risk of coagulopathy may increase.

Anesthesia, Epidural↗

PubMed1996

[Delayed hypoxia after the surgical correction of femoral neck fracture].

We investigated perioperative blood gas changes in 26 patients scheduled for surgical correction of femoral neck fracture under epidural anesthesia. Arterial blood gases during spontaneous air respiration were measured eight times during the femoral neck prosthetic replacements (n = 16), and four times during osteosynthesis (n = 10). In the patients who received femoral neck replacements using bone cement (n = 8), arterial oxygen tension decreased significantly four hours after insertion of prosthesis, and did not recover during two postoperative days. In contrast, in the patients who received cementless femoral neck replacements (n = 8), arterial oxygen tension tended to decrease but not significantly, and returned to normal on the second postoperative day. In the patients who received osteosynthesis, arterial oxygen tension did not change. We suspected that the causes of delayed hypoxia in the femoral neck replacements were vascular endothelial cell injury in the lung by free fatty acid originating from fat embolism, and/or microthrombosis resulting from activated coagulation system. Bone cement was thought to intensify fat embolism because of elevated intramedullary pressure in the femur.

Aged↗

PubMed1995

Transcriptional regulation of the Sex-lethal gene by helix-loop-helix proteins.

Somatic sex determination in Drosophila depends on the expression of Sex-lethal (Sxl), whose level is determined by the relative number of X chromosomes and sets of autosomes (X:A ratio). The first step in regulation of Sxl expression is transcriptional control from its early promoter and several genes encoding transcription factors of the helix-loop-helix (HLH) family such as daughterless (da), sisterless-b (sis-b), deadpan (dpn) and extramacrochaetae (emc) have been implicated. By the use of transfection assays and in vitro binding experiments, here we show that da/sis-b heterodimers bind several sites on the Sxl early promoter with different affinities and consequently tune the level of active transcription from this promoter. Interestingly, our data indicate that repression by the dpn product of da/sis-b dependent activation results from specific binding of dpn protein to a unique site within the promoter. This contrasts with the mode of emc repression, which inhibits the formation of the da/sis-b heterodimers. These results reveal the molecular mechanisms by which Sxl gene transcription is positively or negatively regulated to control somatic sex determination.

Animals↗

PubMed1995

[A case of histological complete remission by preoperative intraarterial infusion chemotherapy].

We experienced a case of histological complete remission by preoperative intraarterial infusion chemotherapy in the treatment of histologically diagnosed endometrial cancer of well differentiated type. MRI demonstrated invasion of the myometrium to a depth of more than 1/2 and left partial parametrium. This patient was given intra-uterine arterial infusion chemotherapy twice (CDDP & ADM ia, CPA iv). Radical hysterectomy was done 3 weeks after intraarterial infusion chemotherapy. The extirpated uterus was histologically complete remission. Thus, in this case shows that intraarterial infusion chemotherapy is effective for neo-adjuvant chemotherapy of endometrial cancer.

Adenocarcinoma↗

PubMed1995

[Hypoxemia during cesarean section--evaluation of venous air embolism by transesophageal echocardiography].

We studied the incidence and cause of hypoxemia during Cesarean section under general anesthesia. Arterial oxygen desaturation (< or = 95%) occurred in 6 of 28 patients (21%). Venous air embolism (VAE) was detected in 7 of 28 subjects (25%), but the severity of which was mild and was not associated with oxygen desaturation. While, there were significant differences in obesity index, preoperative respiratory function, and PaO2 after the induction of anesthesia between the patients with and without oxygen desaturation. Our results suggest that hypoxemia may occur frequently during Cesarean section under general anesthesia, but is not caused by VAE, and is related with the physiological changes associated with pregnancy.

Adult↗

PubMed1995

[Bronchospasm during anesthesia in a patient with Prader-Willi syndrome].

A patient with Prader-Willi syndrome developed bronchospasm during anesthesia. The patient was a 9-year-old boy and was scheduled for orchiopexy. His psychomotor development was delayed, and at 12 months of age he was diagnosed as Prader-Willi syndrome by chromosomal examination. The patient weighed 17 kg, was 111 cm tall, and had no symptom of upper respiratory infection preoperatively. Preoperative examinations were normal except supraventricular extrasystole in electrocardiogram. Following administration of scopolamine 0.15 mg intramuscularly as preanesthetic medication, anesthesia was induced smoothly by slow induction using N2O-O2-sevoflurane. However, right after endotracheal intubation with vecuronium 2 mg, remarkable stridor was noticed. Despite hyperventilation, the patient exhibited hypercapnia, and the diagnosis of bronchospasm was made. Aminophylline and steroid were administered intravenously and halothane was inhaled instead of sevoflurane. The bronchospasm was improved gradually and surgery was finished. Prader-Willi syndrome is an uncommon disease first reported by Prader in 1956 and characterized by hypotonia, hypomentia, hypogonadism and obesity. In the perioperative management for a patient with Prader-Willi syndrome, special attention must be paid to the abnormalities in the upper and lower respiratory systems.

Adrenergic beta-Agonists↗

PubMed1994

[Effects of fructose on left ventricular function during hypoxia].

The effects of fructose on cardiac function and myocardial metabolism during hypoxia were compared with those of saline infusion in the anesthetized mongrel dogs. Hypoxia was induced with inhalation of low fraction of oxygen (PaO2 = 15 mmHg) for two hours. Fructose (N = 7) was infused intravenously at a rate of 1 g.kg-1.h-1 and saline (N = 7) was infused at 5 ml.kg-1.h-1, in the same volume as fructose infusion. Both infusions were started at the induction of hypoxia. In the fructose group, two of seven dogs died within 90 min, and other dogs within 120 min. After 120 min, only one dog survived. In saline group, three of seven dogs died within 60 min, another within 90 min, and three others died within 120 min. In both groups, the dogs with cardiac arrest at an early period tended to show low levels of blood glucose and high levels of lactic acid. Blood glucose levels were similar in both groups, but % increase of blood glucose from control and myocardial glucose uptake tended to be higher in fructose group than in saline group. Blood lactic acid (LA) levels increased significantly in both groups, but, in fructose group, LA levels were higher, and arterial pH decreased more than those in saline group. In fructose group maximum rate of rise of left ventricular pressure (LV dp/dt max) correlated with intramyocardial pH (r = 0.834, P < 0.01), but not with LA levels nor with difference of blood lactic acid from control (d-LA).(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis, Lactic↗

PubMed1994

[Effects of diltiazem hydrochloride on blood gases].

The effects of diltiazem, Ca ion channel blocker, on arterial blood gases were evaluated in 50 patients (G-I: 24 patients undergoing abdominal surgery, G-II: 26 patients undergoing non-abdominal surgery). Diltiazem hydrochloride was administered to prevent intraoperative hypertension as a bolus (5 mg) followed by a continuous infusion (5-10 micrograms.kg-1.min-1). Arterial blood gases were analyzed just before, as well as 5 and 15 min after the administration of diltiazem. In G-I, arterial blood oxygen tension decreased significantly (P < 0.001) from 210.8 +/- 42.4 to 197.7 +/- 50.2 mmHg 5 min after infusion, and to 193.2 +/- 53.4 mmHg 15 min after; while there was no significant difference in G-II. Diltiazem infusion may deteriorate oxygenation in patients undergoing abdominal surgery, and therefore oxygenation should be carefully monitored.

Abdomen↗

PubMed1994

[Severe hypoxemia during cesarean section].

We describe three cases in which severe hypoxemia occurred during cesarean section. The first and second patients showed low oxygen saturation (91, 90%, respectively) on their arrival at the operation room, and hypoxemia deteriorated rapidly after the induction of anesthesia. During surgery low oxygen saturation, ranging from 90 to 95%, persisted until the beginning of spontaneous respiration. In the third patient, oxygen saturation fell suddenly to 93% after the delivery of a neonate, and the arterial blood gas analysis revealed Pao2 68.5 mmHg with 38% oxygen. Hypoxemia was transient and resolved at the end of operation. Parturients have been reported to be likely to develop hypoxemia physiologically. Apnea for a short interval during tracheal intubation may cause severe hypoxemia in parturients compared with normal subjects. Ritodrine, a beta 2 stimulator, which was administered in the first and second patients just prior to operation, may be one of the factors leading to hypoxemia because of its inhibition of hypoxic pulmonary vasoconstriction. Venous air embolism (VAE) may occur frequently during cesarean section, especially during repair of the uterus. VAE may have caused hypoxemia in the third patient. In conclusion, parturients should be monitored carefully with pulse oximetry during cesarean section.

Adult↗

PubMed1994

[Effects of NaHCO3 on cardiac function and metabolism during hypoxic metabolic acidosis--1: Slow infusion of NaHCO3].

Effects of NaHCO3 on metabolic acidosis during hypoxia and after reoxygenation were studied in 18 anesthetized dogs. Metabolic acidosis was produced by inhalation of low fraction of oxygen (9%) for 2 hours. NaHCO3 1M was infused intravenously during hypoxia (n = 12) and 30 minutes after reoxygenation (n = 6) at the rate of 100 ml.min-1 (total 0.2 x body weight x base excess mEq). After reoxygenation, NaHCO3 significantly increased blood and intramyocardial pH and decreased blood lactate (LA) level. Maximal rate of rise of left ventricular pressure (LV dP/dt max) and cardiac index (CI) increased significantly, and left ventricular end-diastolic pressure (LVEDP) and LVEDP/left ventricular pressure (LVP) were unchanged. During hypoxia, NaHCO3 also significantly increased blood and intramyocardial pH but those changes were less than the values after reoxygenation, while blood LA level increased significantly. LVP and LV dP/dt max tended to decrease, while LVEDP and LVEDP/LVP increased significantly. In 8 of 12 dogs, myocardial glucose uptake increased but was not correlated with myocardial LA uptake and LV dP/dt max. Blood LA level correlated significantly with LV dP/dt max (r = 0.534, P < 0.01). It appears that during hypoxia, differing from reoxygenation, NaHCO3 may depress cardiac function due to intramyocardial acidosis.

Acidosis, Respiratory↗