Biomedical subjects

M Sudo

Publications and source records attributed to M Sudo.

At least 37 records · Page 2Linked to original sources

PubMed2001

[Assessment of stage IIB lung cancer from the pathological factors].

In our experience, the prognosis of patients with pathological T3N0M0 lung cancer is generally poor, the 5-year survival rate being almost the same as that of patients with stage IIIA disease. Thus, we assessed patients with stage IIB disease by examining the pathological factors, lymphatic invasion, vessel invasion, histological type, differentiation, tumor size, and node dissection. Lymphatic invasion was found to be positive in 20 of 21 cases, patients with T3N0M0 lung cancer, and all of those with positive vessel invasion had a significantly poor prognosis. This indicates that positive lymphatic and vessel invasion could be a prognostic factor predicting a poor outcome. Patients with T3N0M0 lung cancer that are found to have this poor prognostic factor may not be diagnosed as having stage IIB disease.

Aged↗

PubMed2001

[Successful management of a patient who developed intra-operative pulmonary tumor embolism].

A 68-year-old female with retroperitoneal tumor extending into the inferior vena cava (IVC) developed massive pulmonary tumor embolism during removal of the tumor. Because of her unstable hemodynamics, emergency pulmonary embolectomy under cardiopulmonary bypass was performed. Successful management of her intra- and post-operative persistent right heart failure led to a satisfactory postoperative course without serious neurological complications. In peri-operative management of a patient with an extended tumor into IVC, prevention of the embolism, detection of the pulmonary embolism and treatment of intra- and post-operative right heart failure are important.

Aged↗

PubMed2001

Comparison of nutrient budgets between three forested mountain watersheds on granite bedrock.

The budgets of nutrients and major ions between the input flux from atmospheric deposition and the output flux to streams were measured on three forested small mountain watersheds, Aburahi-N (23.8 ha), Aburahi-S (3.8 ha, 2 km south from Aburahi-N) and Myokoji (1.77 ha, 28 km northwest from Aburahi-N), located at 34-35 N and 136 E around the central part of Japan. The bedrock of the watersheds is granite. The main vegetation of Aburahi-N and Aburahi-S was planted with Japanese cypress (Chamaecyparis obtusa Sieb. et Zucc), and Myokoji was a secondary forest growing deciduous broadleaf trees and Japanese red pine. The chemical analysis of the stream waters was carried out once a week at Aburahi-N from 1987 to 1991, at Aburahi-S from 1995 to 1998, and at Myokoji from 1991 to 1993. Wet and dry depositions were collected every month at Aburahi-N. The annual mean concentrations of total nitrogen (TN) of the stream water of Aburahi-N, Aburahi-S and Myokoji were 0.408, 0.614 and 0.349 mg/l, respectively, total phosphorus (TP) contents were 0.0074, 0.0046 and 0.0096 mg/l, and the potassium ion (K+) contents were 0.83, 0.49 and 0.77 mg/l. The average annual output fluxes of TN from the watersheds of Aburahi-N, Aburahi-S and Myokoji were calculated to be 5.85, 4.10 and 12.7 kg/ha/y, TP 0.131, 0.045 and 0.280 kg/ha/y, K+ 9.63, 3.23 and 9.70 kg/ha/y, and discharge 1062, 508 and 1265 mm/y, respectively. The annual outputs tended to increase as the annual precipitation increased. The average annual input fluxes of TN, TP and K+ for six years from 1990-1998 were 12.5, 1.31 and 7.64 kg/ha/y, respectively, and the precipitation averaged 1449 (1019-1947) mm/y.

Ecosystem↗

PubMed2000

Organic change of effusion in the mastoid in otitis media with effusion and its relation to attic retraction.

To try to solve the pathogenesis of severe attic retraction viewed from mastoid condition, we examined the residual soft tissue density (RSTD) in the mastoid by computed tomography (CT) in 85 patients (107 ears) with otitis media with effusion (OME) 3 months after tympanostomy tube insertion or later. The incidence of RSTD in the mastoid was significantly higher in OME of adults (52.6%) than in children (24.1%). Ears with severe attic retraction had RSTD significantly more frequently (80%) than those with no or mild attic retraction, and many of the mastoids with severe attic retraction were occupied totally by RSTD. The area of the mastoid (mastoid pneumatization) was significantly smaller, and CT density of the mastoid (sclerotic tendency) was significantly higher in ears with RSTD than in those without. RSTD after tympanostomy tube insertion in the mastoid indicating organic change of effusion was considered one of the important factors relating to the pathogenesis of severe attic retraction.

Adolescent↗

PubMed2000

A study on liquid-liquid distribution based on single picoliter droplets and in situ electrochemical measurements.

A microelectrode technique combined with the microcapillary injection/manipulation of a single organic droplet in water was developed. The technique was applied to the study of the distribution of a ferrocene derivative across a single-picoliter-nitrobenzene-droplet/water interface and to the simultaneous in situ electrochemical determination of the distributed solute in the picomole-femtomole range. The liquid-liquid distribution processes were discussed in terms of droplet size and solute concentration (in water) dependencies of the interfacial mass transfer rate.

Electrochemistry↗

PubMed2000

Postnatal development of the tympanic cavity: a computer-aided reconstruction and measurement study.

A computer-aided 3-D reconstruction and measurement method was used to assess postnatal volume and height changes in the tympanic cavity. Materials used were 14 normal human temporal bones obtained from 6 infants (under 1 year of age) and 8 adults (over 18 years of age). After defining the boundaries of the tympanic cavity, its total volume and height and the volume and height of the epitympanum, mesotympanum and hypotympanum were measured. The relationship between the volume of the tympanic cavity and age, and the correlation between the volume of the tympanic cavity and the grade of pneumatization of the air cells were also studied. The average volume of the tympanic cavity in adults (640.1+/-69.1 mm3, n = 8) was about 1.5 times larger than the volume of the infant cavity (451.7+/-68.2 mm3, n = 6). The hypotympanum increased most postnatally and the mesotympanum least. The volume of the tympanic cavity increased in proportion to increasing pneumatization in bone surrounding the cavity. The postnatal increase in the height of the tympanic cavity appears to be the major contributor to the increase in volume of the cavity. Postnatal changes in the tympanic cavity have clinical implications.

Adolescent↗

PubMed2000

The comparative effects of propofol versus thiopental on middle cerebral artery blood flow velocity during electroconvulsive therapy.

UNLABELLED: Electroconvulsive therapy provokes abrupt changes in both systemic and cerebral hemodynamics. An anesthetic that has a minor effect on cerebral hemodynamics might be more suitable for patients with intracranial complications, such as cerebral aneurysm. The purpose of our present study was to compare the effects of thiopental and propofol on cerebral blood flow velocity. We continuously compared cerebral blood flow velocity at the middle cerebral artery (MCA) during electroconvulsive therapy, using propofol (1 mg/kg, n = 20) versus thiopental (2 mg/kg, n = 20) anesthesia. Systemic hemodynamic variables and flow velocity at the MCA were measured until 10 min after the electrical shock. Heart rate and arterial blood pressure increased in the thiopental group until 5 min after the electrical shock. In the propofol group, an increase in mean blood pressure was observed to 1 min after the electrical shock. Mean flow velocity at the MCA decreased after anesthesia in both groups, and increased at 0.5-3 min after the electrical shock in the thiopental group and at 0.5 and 1 min after the shock in the propofol group. The flow velocities at 0.5-5 min after the electrical shock were significantly more rapid in the thiopental group compared with the propofol group. ¿abs¿ IMPLICATIONS: Cerebral blood flow velocity change, measured by transcranial Doppler sonography during electroconvulsive therapy, was minor using propofol anesthesia compared with barbiturate anesthesia. Propofol anesthesia may be suitable for patients who cannot tolerate abrupt cerebral hemodynamic change.

Adolescent↗

PubMed2000

Sensitization, desensitization and stimulus-induced recovery of trigeminal neuronal responses to oral capsaicin and nicotine.

Repeated application of capsaicin at a 1-min interstimulus interval (ISI) to the tongue induces a progressively increasing irritant sensation (sensitization), followed after a rest period by reduced sensitivity to further capsaicin (desensitization). Sequential reapplication of capsaicin induces irritation that eventually increases to initial levels: stimulus-induced recovery (SIR). In contrast, repeated application of nicotine elicits a declining irritant sensation across trials. To investigate possible neural correlates of these phenomena, we recorded from single units in superficial laminae of the dorsomedial trigeminal subnucleus caudalis (Vc) that responded to noxious thermal (54 degrees C) and chemical (1 M pentanoic acid) stimulation of the tongue of anesthetized rats. We then recorded responses to either capsaicin (330 microM) or nicotine (0.6 M), delivered either once, repeatedly at 1-min ISI, or continually by constant flow. After the initial capsaicin application and a rest period, the capsaicin was reapplied in the identical manner to test for SIR. The mean response of 14 Vc units to sequential application of pentanoic acid did not vary significantly across trials, indicating lack of tachyphylaxis or sensitization. The averaged response of 11 Vc units to repeated capsaicin increased significantly across the first eight trials and then plateaued. Following the rest period, spontaneous firing had returned to the precapsaicin level. With capsaicin reapplication, the averaged response increased again after a significant delay (due to desensitization), but did not reattain the peak firing rate achieved in the initial series (partial SIR). Constant-flow application of capsaicin induced an identical sensitization followed by nearly complete SIR. A single application of capsaicin induced a significant rise in firing in eight other units, but the rate of rise and maximal firing rate were both much lower compared with repetitive or constant-flow capsaicin. When capsaicin was reapplied once after the rest period, there was no change in firing rate indicating absence of SIR. These results indicate that maintenance of the capsaicin concentration induces a progressive increase in neuronal response that parallels sensitization. With recurrent capsaicin application, desensitization can be overcome to result in a delayed recovery of Vc responses similar to SIR. In contrast, the averaged response of 17 Vc units to repeated or constant-flow application of nicotine increased only over the first 3 min, and then decreased to spontaneous levels even as nicotine was still being applied. These results are consistent with the decrease in the perceived irritation elicited by sequential application of nicotine in humans.

Administration, Oral↗

PubMed2000

Soft-wall reconstruction for cholesteatoma surgery: reappraisal.

OBJECTIVE: To reevaluate the validity of the soft-wall reconstruction method of the posterior meatal wall in surgeries for cholesteatomas. STUDY DESIGN: Retrospective case review. PATIENTS: Subjects consisted of 52 patients (54 ears) with fresh cholesteatoma (excluding residual or recurrent cholesteatomas) who were operated by the soft-wall reconstruction method in our clinic and observed for more than 2 years after surgery, and 29 patients (29 ears) who were operated by canal-wall-down and open method. MAIN OUTCOME MEASURES: Postoperative period required for complete epithelization (dry ear), hearing, and incidence of the residual and recurrent cholesteatomas were compared with those operated by canal-wall-down and open method. The postoperative conditions of the soft posterior meatal wall was also investigated. RESULTS: Postoperative period to be a dry ear was significantly shorter in the soft-wall reconstruction group than in the canal-wall-down and open group (Student's t-test, t = 2.99, p < 0.01). There was no significant difference in the postoperative hearing or incidence of residual and recurrent cholesteatomas between the two groups. CONCLUSIONS: These results indicate that the soft-wall reconstruction method seems more versatile than the canal-wall-down and open method for cholesteatoma surgery.

Acute Disease↗

PubMed2000

[Asthma death among adults in Japan 1995-1997. Analysis of 295 cases reported questionnaires sent to hospitals with more than 100 beds. Asthma Death Investigation Committee].

To clarify recent trends in adult asthma mortality, the Asthma Death Investigation Committee of Japan studied the clinical characteristics of 295 patients who died of asthma between 1995 and 1997. Males were slightly more than females among the death cases. Approximately half of the patients ranged in age from 60 to 79 years. Tendency to increase of death among young male adults continued. One third of the patient deaths involved the asphyxic type, while status asthmaticus was the cause death in 21.9%. Half of the asthmatics died in hospitals or emergency rooms, and places where the fatal attacks occurred were mainly patients' houses. The main cause fatal asthma attacks was respiratory infection, followed by fatigue, stress, and discontinuation of medication. Most of the patients were classified moderate or severe type of asthma 1 month before death. Histories of life-threatening attacks and hospitalization due to severe attacks, irregular visits to the hospital, low compliance, and insufficiency of corticosteroid treatment were suggested as the main risk factors in adult asthma deaths.

Adolescent↗

PubMed2000

Isoflurane depresses electroencephalographic and medial thalamic responses to noxious stimulation via an indirect spinal action.

UNLABELLED: Anesthetics such as isoflurane act in the spinal cord to suppress movement in response to noxious stimulation. Spinal anesthesia decreases hypnotic/sedative requirements, possibly by decreasing afferent transmission of stimuli. We hypothesized that isoflurane action in the spinal cord would similarly depress the ascending transmission of noxious input to the thalamus and cerebral cortex. In six isoflurane-anesthetized goats, we measured electroencephalographic (EEG) and thalamic single-unit responses to a clamp applied to the forelimb. Cranial bypass permitted differential isoflurane delivery to the torso and cranial circulations. When the cranial-torso isoflurane combination was 1.3% +/- 0.2%-1.0% +/- 0.4% the noxious stimulus did not evoke significant changes in the EEG or thalamic activity: 389 (153-544) to 581 (172-726) impulses/min, (median, 25th-75th percentile range, P: > 0.05). When the cranial-torso isoflurane combination was 1.3% +/- 0.2%-0.3% +/- 0.2%, noxious stimulation increased thalamic activity: 804 (366-1162) to 1124 (766-1865) impulses/min (P: < 0.05), and the EEG "desynchronized": total EEG power decreased from 25 +/- 20 microV(2) to 12 +/- 8 microV(2) (P: < 0.05). When the cranial-torso isoflurane was 1.7% +/- 0.1%-0.3% +/- 0.2%, the noxious stimulus did not significantly affect thalamic: 576 (187-738) to 1031 (340-1442) impulses/min (P: > 0.05), or EEG activity. The indirect torso effect of isoflurane on evoked EEG total power (12.6 +/- 2.7 microV(2)/vol%, mean +/- SE) was quantitatively similar to the direct cranial effect (17.7 +/- 3.0 microV(2)/vol%; P: > 0.05). These data suggest that isoflurane acts in the spinal cord to blunt the transmission of noxious inputs to the thalamus and cerebral cortex, and thus might indirectly contribute to anesthetic endpoints such as amnesia and unconsciousness. IMPLICATIONS: Isoflurane action in the spinal cord diminished the transmission of noxious input to the brain. Because memory and consciousness are likely dependent on the "arousal" state of the brain, this indirect action of isoflurane could contribute to anesthetic-induced amnesia and unconsciousness.

Anesthetics, Inhalation↗

PubMed1999

Modifications in electrospray tandem mass spectrometry for a neonatal-screening pilot study in Japan.

In a neonatal-screening pilot study for inherited disorders in organic acid and amino acid metabolism, we analyzed butyrated acylcarnitines and amino acids in blood spots of more than 20,000 newborns by electrospray tandem mass spectrometry. In order to screen urea cycle disorders, we performed multiple scanning functions with additional stable isotope-labelled internal standards, since such reported functions as neutral loss of m/z 102 or 109 for butyrated amino acids were not sufficient. Arginine levels were measured with arginine-13C6. Hypocitrullinemia for the screening of some urea cycle disorders was detectable by measurement with synthesized citrulline-d6, although we did not find any such disorders. In the acylcarnitine analysis, we found a patient with propionic acidemia, who has been treated effectively. The increasing false positive rate due to the use of pivalic acid-containing antibiotics in the diagnosis of isovaleric acidemia was a problem in Japan.

Calibration↗

PubMed1999

Expression of recombinant NMDA receptors in hippocampal neurons by adenoviral-mediated gene transfer.

N-methyl-d-aspartate (NMDA) receptors have attracted a great deal of attention because they are intimately involved in brain development, synaptic plasticity and a variety of neurological disorders. The ability to artificially alter the properties of NMDA receptors in central nervous system (CNS) neurons would be useful for elucidating the physiological roles of these receptors. It would also raise the possibility of gene therapy of neurological diseases caused by malfunction of NMDA receptors. In this study, we constructed three recombinant adenoviruses encoding rat NMDA receptor subunit cDNAs, NMDAR1 (NR1), NMDAR2B (NR2B) and mutant NR1(N598R) in which the asparagine (N) site of the wild-type NR1 was replaced with arginine (R) by site-directed mutagenesis. PC12 cells co-infected with recombinant adenoviruses bearing NR1 and NR2B cDNAs expressed conventional NMDA receptors that were permeable to Ca2+ and sensitive to Mg2+, whereas those with viruses bearing NR1(N598R) and NR2B cDNAs expressed Ca2+-impermeable and Mg2+-insensitive receptors. When rat hippocampal neurons in culture were infected with NR1(N598R) and NR2B viruses, both Ca2+ permeability and Mg2+ sensitivity of NMDA receptors were markedly reduced in the infected neurons. Excitatory postsynaptic currents (EPSCs) mediated by NMDA receptors also became much less sensitive to Mg2+. Thus, the NR1(N598R)/NR2B receptors were more dominant than the native NMDA receptors in the infected neurons, and the former receptors introduced by the adenoviral vectors functioned as postsynaptic receptors. These results indicate that the functional properties of postsynaptic NMDA receptors can be manipulated by gene transfer technology using adenoviral vectors.

Adenoviridae↗

PubMed1999

Postsynaptic expression of Ca2+-permeable AMPA-type glutamate receptor channels by viral-mediated gene transfer.

The ability to artificially express a particular receptor protein in the postsynaptic sites of neurons in the central nervous system (CNS) would be useful for the study of synaptic function of cloned receptor genes as well as for gene therapy of neurological disorders caused by dysfunction of postsynaptic receptors. In this study, we aimed to express the cDNA of unedited GluR2 subunit of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptor that forms inwardly rectifying and Ca2+-permeable channel in CNS neurons by using adenoviral-mediated gene transfer. For this purpose, we have constructed a recombinant adenovirus bearing an expression-switching unit, where the unedited GluR2 cDNA can be activated by the Cre recombinase-mediated excisional deletion of a stuffer DNA interposed between the promotor and the coding region. When PC12 cells were infected with this recombinant adenovirus together with an adenovirus expressing Cre recombinase, the inwardly rectifying and Ca2+-permeable AMPA receptor channels were expressed in nearly 100% of infected cells. Two days after co-infection of cultured rat hippocampal neurons with these adenoviruses, fast excitatory neurotransmission in the glutamatergic synapse was mediated predominantly by the inwardly rectifying and Ca2+-permeable AMPA receptor channels. This indicates that the native AMPA receptors in the postsynaptic sites of the glutamatergic synapse are replaced rapidly with recombinant receptors newly produced by the viral-mediated gene transfer.

2-Amino-5-phosphonovalerate↗

PubMed1999

The diagnostic and prognostic value of eardrum mobility in otitis media with effusion.

Diagnostic and prognostic values of eardrum mobility were determined by pneumatic otoscopy in 37 patients (56 ears) having otitis media with effusion (OME). Eardrum mobility was impaired or lost in less than half of the ears (46.4%), while a tympanogram detected 77.8% of OME. In 27 of the 37 patients (42 of the 56 ears), aeration of the middle ear space was examined by CT and demonstrated that the presence or absence of aeration was significantly correlated with the presence or absence of eardrum mobility. In another 38 children (62 ears with OME), effect of antibiotics was correlated with eardrum mobility before treatment, and the improvement rate was found to be significantly higher in ears with positive mobility of eardrum (34.3%) than in ears without eardrum mobility (10.0%). These results indicate that eardrum mobility is a good prognostic indicator of OME rather than its diagnostic indicator alone.

Acoustic Impedance Tests↗

PubMed1999

Factors affecting recovery of mastoid aeration after ear surgery.

Fifty-six patients after tympanomastoid surgery were examined to determine recovery of mastoid aeration and various pre- and intraoperative factors such as eustachian tube (ET) function, how the mastoid mucosa had been treated during surgery and whether or not a large silastic sheet had been placed in the middle ear or a ventilation tube used. Mastoid aeration recovery was confirmed by computed tomography in 27 of the 57 cases (47%) within 12 months of surgery. Among the factors examined, preservation of the epitympanic mucosa was found to be most important in mastoid aeration recovery. Use of a large silastic sheet to cover the area from the bony ET and tympanic cavity to epitympanum, aditus ad antrum or antrum was found to be of some help in recovery mastoid aeration after complete resection of the mucosa and mastoid air cells. Preoperative ET function, anterior tympanotomy and use of a ventilation tube did not influence recovery.

Adolescent↗

PubMed1999

Studies on spatial orientation and posture control and changes in otolith function due to linear acceleration loading.

Otolith function is directly affected by weightlessness at the time of movement in outer space, and changes occur in the mode of response. It has been known for some time that such changes occur in the posture and gait of astronauts just after they return from a trip into space. It is thought that the cause of these changes is disuse atrophy of the antigravity muscles. However, in the present study, experimental subjects underwent repeated linear acceleration loading over a long period of time, and instability of the head and a decrease in posture control, especially in relation to the gait, were observed for the first time. To date, it has been said that the otolith function has a close relationship with ocular counter rolling. However, when the otolith organ was stimulated, the response was seen to be head instability and an irregular effect on the gait. It is surmised that these findings will facilitate future research into the otolith function under gravity-free conditions.

Acceleration↗

PubMed1999

[The effect of propofol as an anticonvulsant].

We observed that propofol was very effective for the refractory general convulsion after surgical operation of cerebral aneurysmal clipping in two patients. The first patient had suffered from asthma. Standard regimens except for thiopental were ineffective for the refractory general convulsion after the operation. So, we administered propofol to the patient, at the dosage of 1 mg.kg-1 intravenously and then, 1 mg.kg-1.hr-1 continuously i.v. Propofol suppressed the general convulsions completely. On the EEG, there were no convulsive spikes. Furthermore, patient's consciousness became clearer during the administration of propofol. The convulsion in the second patient not suffering from asthma, was intractable, too and diazepam, phenytoin, and phenobalbital were not effective. Then, we tried propofol in the same way, and good effect was obtained. Propofol may be an effective medicine for the refractory general convulsion.

Anticonvulsants↗