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Biomedical subjects

F Murakami

Publications and source records attributed to F Murakami.

At least 127 records · Page 7Linked to original sources
PubMed1992

[Valve injury: a new complication of internal jugular vein cannulation].

Although internal jugular vein cannulation is performed commonly, most physicians are not aware of existence of the internal jugular venous valve. This is the only valve between the right atrium of the heart and the brain, and it has an important role of preventing retrograde blood flow and increased back pressure to the brain. In this study, anatomic appearance of human internal jugular valves is described, and the competence of these valves is assessed. We examined also a safe approach to percutaneous cannulation of the internal jugular vein to avoid this complication. In the cadaveric subjects, the internal jugular vein with its valve was removed at the time of autopsy. In the living subjects, to examine the movement of this valve, endoscopic visualization utilizing the superfine fiberscope, and ultrasound techniques were applied. Next, to detect the competence of the jugular venous valve, transvalvular pressure gradients were measured. Nineteen internal jugular valves were obtained from 20 cadaveric subjects. These valves were situated directly above the termination of the internal jugular vein into the inferior bulb. The opening and closing of the valve were easily visualized with both superfine fiberscope and real-time ultrasound technique. Patients with competent valves showed transvalvular pressure gradients of 50-100 mmHg during cough-induced high intrathoracic pressure. Internal jugular venous valve is located 0.5-2.0 cm above the union of the subclavian and internal jugular veins, and the central approach performed at the summit of the cervical triangle has been shown to have a risk of injuring the internal jugular venous valve.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheterization, Peripheral↗
PubMed1992

[A case report of a 63-year-old patient with malignant hyperthermia].

We have experienced a case of fulminant malignant hyperthermia who was a 63-year-old female weighing 44 kg. There was no particular past history nor family history. She underwent right mastoidectomy because of chronic otitis media. Her preoperative physical status was ASA I. She was premedicated with diazepam 10 mg and loxatigine 75 mg P.O. The induction was done with thiamylal 200 mg IV and fentanyl 0.1 mg IV followed by vecuronium 6 mg IV for endotracheal intubation. Intubation was easy and uneventful. Anesthesia was maintained with nitrous oxide 3 l.min-1, oxygen 3 l.min-1 and enflurane 2.0%. Seventy min after the induction of anesthesia, arterial blood gas analysis showed severe respiratory acidosis (PCO2: 63.2 mmHg, pH: 7.27) and it was improved with manual hyperventilation at that time. Pulse rate increased from 80 to 115 b.p.m. 20 minutes later. Then, the patient was ventilated with 100% oxygen, and anesthetic circuits and machine were exchanged for new units. Surgery was postponed. Muscle stiffness of upper extremities was observed and her temperature increased to a maximum of 38.9 degrees C. Surface cooling was started and dantrolene sodium 60 mg and furosemide 20 mg were given intravenously. The patient was transferred to the intensive care unit, and clinical signs improved gradually within one hour. Serum enzymes; CPK, LDH, GOT and GPT increased on the first postoperative day. On the 11 th postoperative day skeletal muscle biopsy was done under local anesthesia with 1% procaine and Ca-induced Ca-release rate test revealed positive for enflurane. This is the oldest patient of malignant hyperthermia reported in Japan.

Anesthesia, Inhalation↗
PubMed1991

Synapses formed by ectopic corticofugal axons: an electron microscopic study of crossed corticorubral projections in kittens.

The corticorubral projections in newborn kittens are bilateral, while the projections are unilateral in adults. We addressed the question whether or not the crossed corticorubral projection in kitten forms synaptic contacts in the red nucleus. The neurons in the sensorimotor cortex of the kitten were labeled by Phaseolus vulgaris-leucoagglutinin or biocytin. Electron microscopic observations revealed that corticofugal axons form synapses both in the contralateral and the ipsilateral red nucleus; most of them were on small postsynaptic profiles, possibly dendritic spines or distal dendrites.

Animals↗
PubMed1991

Ultrastructural localization of telencephalin, a telencephalon-specific membrane glycoprotein, in rabbit olfactory bulb.

Localization of a telencephalon-specific glycoprotein, telencephalin (TCLN), in the olfactory bulb of the rabbit was studied with an electron microscope. Anti-TCLN antisera appeared to stain plasma membrane, Golgi apparatus and multivesicular bodies of granule cells which are local circuit interneurons in the bulb. Principal neurons, mitral and tufted cells, were not immunoreactive. No glial cells showed immunoreactivity. Thus, expression of telencephalin is specific not only to the telencephalic segment of the brain, but also to the neuronal types.

Animals↗
PubMed1991

Lesion-induced establishment of the crossed corticorubral projections in kittens is associated with axonal proliferation and topographic refinement.

The aberrant crossed corticorubral projection of the cat, which is very weak compared to the uncrossed one at about 1 month postnatal, becomes pronounced following unilateral lesions of the sensorimotor cortex. In order to determine whether or not terminal proliferation of pre-existing axons underlie this enlargement, the morphological changes of the crossed axons were examined, using the anterograde tracer Phaseolus vulgar- is leukoagglutinin (PHA-L). The crossed corticorubral axons in normal kittens were mostly simple in morphology with infrequent branching and did not often exhibit growth-cone-like axonal endings at 1 month postnatal. Two to 5 days after unilateral lesions of the sensorimotor cortex placed at this age, the axons were as simple as those in normal animals but ended in growth cones more frequently. Seven to 10 days post-lesion, the axons often bore side-branches which ended in growth cones. Two to 3 weeks post-lesion axons with sprays of finger-like fine sprouts occurred throughout the projection zone. There was no clear topography for the crossed projection in normal animals, but at 1-2 weeks post-lesion the axons started to show a certain amount of localization in the regions of the red nucleus which corresponded to the densely innervated region on the ipsilateral side. The topography of the crossed projections roughly mirrors that of the ipsilateral projection at about 1 month post-lesion. Thus, the lesions of the sensorimotor cortex induce substantial growth and proliferation of the crossed corticorubral axons. The post-lesion changes in axonal morphology and topographic refinement are reminiscent of developmental events. It is likely that the lesions permit the crossed axons, which normally fail to develop, to develop like the uncrossed ones.

Aging↗
PubMed1991

[Characteristics and mechanism of pyelorenal backflow correlated to renal pelvic pressure].

The present study was conducted to examine the characteristics of pyelo-renal backflow related with the changes in renal pelvic pressure. Forty rabbits weighting approximately 3.0 kg were used in this experiment. The renal pelvis was continuously perfused with PSP solution through the double lumen catheter placed above the ureteropelvic junction. The renal pelvic pressure was also recorded during the intrapelvic perfusion. Simultaneously, PSP concentrations in blood and urine excreted from the contralateral kidney were measured. During the intrapelvic perfusion with PSP solution, PSP blood concentration began to increase immediately and reached maximum within 1 or 2 minutes after a start of perfusion. Then, its concentration gradually decreased toward the constant, low levels. The urinary concentration of PSP showed the same change as the blood concentration with a time lag of 1 or 2 minutes. A compartment analysis showed that this backflow curve composed of an early phase and a late phase. The early phase was characterized by a rapid increase and following decrease (exponentially declining) in PSP concentration. The late phase was a portion of constant PSP concentration in the backflow curve. A maximum PSP concentration in the early phase was elevated with an increase in the increment rate of renal pelvic pressure. There was a significant, positive correlation between the maximum PSP urinary concentration and the increment rate of renal pelvic pressure (dp/dt). The constant values of PSP concentration in the late phase could be correlated with neither increment rate nor absolute values of renal pelvic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[A case of adrenal black adenoma associated with Cushing's syndrome].

The patient was a 24-year-old female, who had clinical and laboratory findings of Cushing's syndrome with slight virilizative changes. CT scan, ultrasound sonography and scintigraphy demonstrated that there was a functioning tumor at the right adrenal region. Thus we performed right adrenalectomy. The tumor was a characteristic black adenoma of adrenal gland, and it microscopically consisted of compact cells with remarkable intracellular pigmented granules. Thirty-two cases of functioning adrenal black adenoma have been reported in our country and all of them were associated with Cushing's syndrome.

Adenoma↗
PubMed1991

[The effect of dopamine or dobutamine on plasma concentration of magnesium in dogs].

Plasma magnesium (Mg) concentration of dogs was determined with atomic absorption spectrophotometry during the infusion of dopamine (DOA) or dobutamine (DOB). Other electrolytes were also measured with same samples. Normoventilation was maintained during this experiment in order to avoid the respiratory interference. DOA 15-20 micrograms.kg-1.min-1 decreased Mg concentration significantly. DOB 5-20 micrograms.kg-1.min-1 did not change Mg concentration. Potassium (K) values were almost constant during infusion of both drugs, but DOB reduced K concentration at the dose of 20 micrograms.kg-1.min-1. Ionized calcium ion tended to decrease in DOA and to increase in DOB while the dose of the catecholamines was increased. These were not significant changes. These changes of concentration returned to control values 1 hour after stopping drug administrations. We speculate that beta-receptor, especially beta 2-receptor stimulation by DOA is responsible for the decrease of Mg in the mechanism of Mg uptake into cells of such tissues as liver or muscle.

Animals↗
PubMed1990

Ipsilateral interpositorubral projection in the kitten and its relation to post-hemicerebellectomy plasticity.

Hemicerebellectomy has been reported to induce aberrant ipsilateral projection from the nucleus interpositus (IN) of the remaining hemisphere to the red nucleus (RN) in the kitten but not in adult cats. The cellular mechanisms for this age-at-lesion effect were investigated. The experiments were designed to compare interpositorubral (IN-RN) projections in normal kittens and in kittens hemicerebellectomized at corresponding ages. A sparse ipsilateral IN-RN projection was found in normal kittens aged 7-16 postnatal days (PND) with the PHA-L method, but was not found in those aged 26-43 PND. Among the hemicerebellectomized kittens, ipsilateral IN-RN projections were observed only in those which received the lesion on PND 17 or earlier. Such temporal coincidence between the two events strongly suggests that the exuberant ipsilateral IN-RN projection in normal kittens is related to the establishment of the aberrant ipsilateral IN-RN projection observed after hemicerebellectomy. This notion is strengthened by other lines of evidence; the fibers projecting to the ipsilateral RNs appeared to enter the nucleus from the contralateral one by recrossing the midline between them in both the normal and the lesioned animals. In kittens in which hemicerebellectomy induced the aberrant ipsilateral projection, labeling of fibers within the ipsilateral RNs was much more extensive than that in the normal kittens, while labeling on the pathway of the projection was comparable to that in the normal animals. These observations support the interpretation for aberrant projections observed after a neonatal lesion as being terminal proliferations of pre-existing exuberant projections.

Animals↗
PubMed1990

Postnatal development of crossed and uncrossed corticorubral projections in kitten: a PHA-L study.

Morphological changes in individual corticorubral fibers and the pattern of crossed and uncrossed corticorubral projections were studied during the postnatal development of cats in order to understand cellular mechanisms for restriction of corticorubral projections with development. The anterograde tracer Phaseolus vulgaris leucoagglutinin (PHA-L) was injected into restricted areas of the pericruciate cortex in kittens and PHA-L-labeled axons in the red nucleus were examined at postnatal days (PND) 7-73. In accordance with our previous study (Murakami and Higashi, Brain Res. 1988; 447:98-108), a crossed corticorubral projection was observed in addition to the uncrossed one in every experimental animal. During the early period of development (PND 7-8), swellings of irregular shape were observed along the entire course of the axons and they were often interconnected with extremely fine axonal segments. These axons bifurcated only infrequently and often ended as growth cones. These features were common to both uncrossed and crossed corticorubral axons. At later stages of development (PND 28 or later), the total number of swellings decreased and axonal swellings with smooth contours became dominant. A quantitative examination of axonal branches indicated that axons on the ipsilateral side branch occurred more frequently at later stages of development. However, there was no substantial change in branching frequency for the crossed corticorubral fibers during development. In parallel with morphological changes in individual axons, the crossed projection that was initially relatively abundant was reduced during development. Since a PHA-L injection can be confined to a small region of cortex, topographic projections can easily be detected. At PND 7-8 there was no well-defined topographic order in the ipsilateral corticorubral projection. Adult-like topography was first discernible at PND 13. These observations suggest that the unilateral uncrossed corticorubral projection in the adult cat is achieved at least in part by the formation of axonal arbors in the uncrossed projection. This was accompanied by the failure of crossed fibers to form complex arbors. It is possible that a similar mechanism also operates in the formation of topographic maps.

Aging↗
PubMed1990

Thoracic epidural anaesthesia combined with enflurane anaesthesia reduces atrioventricular conduction in dogs.

Cardiac electrophysiological variables during thoracic epidural lidocaine (TEL) were compared with those during continuous intravenous lidocaine (IVL) infusion in 14 mongrel dogs anaesthetized with enflurane in order to investigate the combined effects of thoracic epidural anaesthesia (TEA) and enflurane anaesthesia on intracardiac conduction. Thoracic epidural lidocaine suppressed intracardiac conduction. Sinus cycle length (SCL) and Atrium-His (AH) interval increased by 9 and 11 per cent respectively (P less than 0.05), 30 min after TEL. Intravenous lidocaine did not increase either SCL or AH. The functional refractory period of the atrioventricular node increased five per cent above the control value 15 min after TEL (P less than 0.05), while it was unchanged in the IVL group. The mean plasma concentrations of lidocaine ranged from 0.48 +/- 0.07 to 1.00 +/- 0.14 micrograms.ml-1 in the TEL group and from 0.98 +/- 0.13) to 1.21 +/- 0.15 micrograms.ml-1 in the IVL group. There were no significant differences in plasma concentrations of lidocaine in both groups during the observation period. Therefore, it is concluded that the depressant effects of TEA on intracardiac conduction were caused by blocking of the sympathetic efferent activity. Caution may be advised in administering TEA when cardiac conduction is already compromised.

Analysis of Variance↗
PubMed1990

Cell attachment to and neurite outgrowth on tissue sections of developing, mature and lesioned brain: the role of inhibitory factor(s) in the CNS white matter.

Chick neocortical cells were cultured on cryostat tissue sections of the brain. Cells preferentially attached to the gray matter of adult rat central nervous system (CNS) tissues. In contrast, they attached to any part of the brain when cultured on developing rat or mature frog brain tissues. Transection of fiber bundles at the superior cerebellar peduncle decussation of adult rat, which reportedly causes regeneration of cerebellofugal axons, made nearby white matter permissive to cell attachment. Superimposition of the gray matter of one section onto the white matter of another, converted the former into a nonpermissive substrate for cell attachment, evidence suggesting that preferential cell attachment to the gray matter of adult rat CNS is due to inhibitory factor(s) localized in the white matter. This inhibitory factor appears to be absent in frog brain and developing rat brain. These results taken together suggest possible involvement of this factor in the regulation of axonal elongation in vivo.

Animals↗
PubMed1990

Formation of crossed and uncrossed projections in the central nervous system.

Cellular mechanisms for decision of laterality of projections are discussed based on the observation of corticorubral and interpositorubral projections in the kitten. In both systems unilateral projections in adults appear to emerge from bilateral projections which occur early in development. Early unilateral lesions of the cerebral cortex or the interpositus nucleus cause persistent bilateral projections. Thus the neurons which eventually make a unilateral projection have the capability of forming synaptic connections with their target cells on both sides of the brain. Aberrant crossed (or uncrossed) projections in neonatal animals retract without forming complex axonal arbors, while those in lesioned animals form complex axonal arbors. Thus, success or failure in forming axonal arbors may be crucial for the maintenance of the aberrant crossed (or uncrossed) projections.

Animals↗
PubMed1990

[S-phase cells of human bladder tumors by in vivo bromodeoxyuridine labeling].

At the time of operation, 10 patients with bladder tumors were given an intravenous infusion of bromodeoxyuridine (BrdU, 250 mg) to label the cells in the DNA synthesis phase (S-phase). The removed tumor specimens were stained immunohistologically using anti-BrdU monoclonal antibody. The percentage of BrdU-labeled cells (S-phase cells) were calculated for each specimen, and expressed as Labeling Index (LI). The average LI of G1, G2 and G3 tumors were 0.9%, 2.3% and 11.9%, respectively. LI was almost parallel to pathological grade. In cases of G2 tumor, LI was varied from 0.2 to 6.2%. The higher LI, the more invasive was the tumor. The patient with the highest LI (12.2%) showed lung metastasis postoperatively and died 6 months after operation. S-phase cells were scattered along the basal layer in G1 papillary tumors, and were observed also near the superficial layer in G2 tumors. In cases of non-papillary tumors, S-phase cells were observed irregularly in various layers. This method will give us useful information on evaluation for malignancy and cell kinetics of bladder tumor.

Aged↗
PubMed1990

[A successful surgical case of DeBakey IIIb dissecting aortic aneurysm in association with right aortic arch].

A case of chronic DeBakey IIIb dissecting aneurysm in association with right aortic arch is reported. A 49-year-old man having encountered an aortic dissecting episode two years ago, was examined more closely because the aneurysm became larger recently. Digital subtraction angiography (intra-venous and intra-aortic) showed DeBakey IIIb dissecting aneurysm associated with a right aortic arch with aberrant subclavian artery. The entry of the aneurysm was in the right descending aorta passing from left thorax to right. The operative indication was for enlarged false lumen in this case. Graft replacement of the aneurysm and closure of the false lumen in the right thorax was performed under partial cardiopulmonary bypass through right thoracotomy. Postoperative digital subtraction angiography showed that dissection was in the abdominal aorta but false lumen in the thorax was completely closed. The patient has made a comeback working. A case of dissecting aortic aneurysm associated with right aortic arch is extremely rare. To our knowledge, this is the third such case reported in Japan, but the first case of a successful graft replacement for dissecting aortic aneurysm associated with right aortic arch.

Aortic Dissection↗
PubMed1990

[Three operated cases of LMT-lesion with chief complaint of syncopal attack].

An urgent aorto-coronary bypass operation (AC-bypass) was made in three patients with unstable angina pectoris, suffering from stenosis of the left main trunk (LMT). All patients were admitted with chief complaints of chest discomfort and syncopal attack. Case 1 was a 71 year-old man who suffered with chest discomfort and syncopal attack. He was admitted to our emergency room by ambulance 40 minutes after the syncopal attack, on January 11, 1989. His blood pressure was 140/96; pulse 84 and regular. The electrocardiogram (ECG) showed right bundle branch block, ST elevation in aVR, aVL and ST depression in all other leads. Coronary arteriogram (CAG) was made urgently and showed 80% stenosis in LMT. The emergency AC-bypass operation was successfully carried out about 3 hours and 10 minutes after the onset of symptoms. Case 2 was a 51 year-old man who suffered from precordial oppression and syncopal attack. He was admitted to our emergency room by ambulance about 1 hour after the attack, on January 17, 1989. His blood pressure was 94/74; pulse 120 and irregular. Chest radiography showed a cardiothoracic ratio of 58% and the ECG disclosed atrial fibrillation, ST elevation in aVR and ST depression in I, II, III, aVF, V1-6. The echocardiogram revealed hypokinetic motion in the antero-lateral wall of the left ventricle. CAG was carried out without delay, and showed 70% stenosis with slit in LMT. An emergency AC-bypass operation was successfully carried out about 3 hours and 50 minutes after the onset of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[The effects of ulinastatin on the release of granulocyte elastase during pancreas surgery].

During a major abdominal surgery, intraoperative manipulation may cause circulatory changes, which lead to release of granulocyte elastase. Twenty one patients were studied to elucidate the release of granulocyte elastase and the inhibitory effect of a protease inhibitor (ulinastatin) on lysosomal enzyme release during pancreas surgery. Patients were divided into 3 groups. Patients in group A served as control. Patients in group B were given ulinastatin 10,000 units.kg-1 intravenously prior to surgery. Patients in group C were given ulinastatin 5,000 units.kg-1 intravenously twice prior to surgery and 3 hours after the start of surgery. The granulocyte elastase was measured by commercially available kits, at 7 points: prior to induction of anesthesia, immediately after tracheal intubation, 30, 60, 120, 180 min after the start of surgery and 30 min after surgery. The plasma level of elastase increased markedly during the operation in group A, it did not increase in groups B and C during the operation. Thirty min after the operation, the plasma level of elastase increased markedly in group A (354 +/- 63 micrograms.l-1), and in group B (396 +/- 167 micrograms.l-1). The plasma level of elastase was restored to normal levels 30 min after the operation in group C. These results indicate that granulocyte elastase values were maintained at significantly higher levels during and after pancreas surgery, and suggest that ulinastatin inhibits the release of granulocyte elastase during pancreas surgery.

Aged↗