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S Namba

Publications and source records attributed to S Namba.

At least 55 records · Page 3Linked to original sources
PubMed1991

Protection against detrimental effects of potyvirus infection in transgenic tobacco plants expressing the papaya ringspot virus coat protein gene.

We obtained transgenic tobacco plants expressing the papaya ringspot virus (PRV) coat protein (CP) gene by transformation via Agrobacterium tumefaciens. Expression was effectively monitored by enzyme-linked immunosorbent assays (ELISA) of crude tissue extracts. Subcloned plants derived from eight original Ro transformants were inoculated with potyviruses: tobacco etch (TEV), potato virus Y (PVY), and pepper mottle (PeMV). Plants that accumulated detectable levels of the PRV CP showed significant delay in symptom development and the symptoms were attenuated. Similar results were obtained with inoculated R1 plants. We conclude that the expression of the PRV CP-gene imparts protection against infection by a broad spectrum of potyviruses.

Base Sequence↗
PubMed1991

[Intercostal nerve cross-anastomosis and DREZ-tomy in a patient with brachial plexus avulsion].

An 18-year-old male with a right brachial plexus injury caused by a motorcycle accident was admitted on October 13, 1988. A detailed examination revealed that the brachial plexus was totally injured. The axon reflex test suggested that the lesion sites were postganglionic in the C5 and C6 nerves, and preganglionic in the C7, C8 and Th1. On December 14, 1988, intercostal nerve cross-anastomosis was performed in the hope that a lost motor function of the right upper extremity could be restored as a first step. An electromyogram 6 months after this anastomotic operation demonstrated synkinesis between the biceps brachialis and the intercostal muscles during deep inspiration. Fifteen months after this operation, active voluntary muscle discharges which were higher than before in amplitude, were provoked. The right elbow flexion was gradually restored independently of respiration. On the other hand, intractable pain with a persistent severe tingling sensation appeared approximately one week after the injury on the lesioned upper extremity. The pain rapidly increased in severity. The DREZ-tomy from C5 to Th1 was performed on March 7, 1989. This has brought complete relief of the intractable pain. A brief discussion was given concerning some aspects of the brachial plexus avulsion and DREZ-tomy.

Adolescent↗
PubMed1990

Nephrogenous cyclic GMP production during NaCl loading and ANP infusion.

To further study the mechanisms of the renal effects of ANP, we examined the effects of NaCl loading and ANP infusion on nephrogenous cGMP production. Six normotensives (NTs) and 7 essential hypertensives (HTs) were placed on 7-day low (3 g/day) and then 7-day high NaCl diets (20 g/day). On the last day of each period, the natriuretic and nephrogenous cGMP responses to ANP infusion at 25 ng/kg/min for 40 min were determined. ANP infusion markedly increased the plasma concentrations of ANP and cGMP and the urinary excretions of Na and cGMP. These changes were accompanied by a rise in nephrogenous cGMP. Increases in nephrogenous cGMP during ANP infusion were not different between HTs and NTs despite a greater natriuretic response in HTs. NaCl loading significantly increased the natriuretic response to ANP infusion in both groups. However, nephrogenous cGMP production induced by ANP infusion was not affected by changes in NaCl intake. Thus, although ANP-induced natriuresis is associated with an increase in nephrogenous cGMP, the natriuretic effect of ANP seems to be modified to a greater extent by indirect mechanisms such as renal perfusion pressure and body fluid volume status.

Adult↗
PubMed1989

Studies on the rectoanal reflex in children and in experimental animals: an evaluation of neuronal control of the rectoanal reflex.

A single-chamber pressure probe for rectal electromanometry was developed which seems to be superior to the complicated multichamber systems not only for clinical but also for experimental purposes. Measurements of rectoanal reflex were carried out in 268 cases with abnormal bowel function, in 103 cases following operation for Hirschsprung's disease, and in 61 cases of imperforate anus to assess postoperative continence. Experimental studies were performed in 36 dogs, 27 of which were used for short-term and 9 for long-term studies. The results of clinical and experimental studies are described and discussed, with accompanying literature. From clinical and experimental studies, the neuronal pathways of the rectoanal reflex are schematized. The normal rectoanal reflex is mediated by both the sacral cord and the myenteric neurons. It is concluded that measurements of the anal resting pressure and the rectoanal reflex constitute a valuable method to distinguish between normal and pathological sacral and myenteric innervation.

Anal Canal↗
PubMed1989

A possible physiological role of atrial natriuretic peptide in body fluid volume regulation.

To study whether or not atrial natriuretic peptide (ANP) is physiologically involved in body fluid volume regulation, we examined the relationship between plasma ANP level and renal function during NaCl loading and ANP infusion. In study I, six normotensives (NTs) and seven hypertensives (HTs) were placed on 7-day low (3 g/day) and then 7-day high NaCl diets (20 g/day). The plasma ANP level increased by 60% (p less than 0.01) on the high NaCl diet. Although the plasma ANP level was higher in HTs than in NTs, the changes in plasma ANP due to NaCl loading were similar between the two groups. Furthermore, increases in urinary Na excretion due to ANP infusion at 25 ng/kg/min were greater for the high NaCl diet than for the low NaCl diet (p less than 0.02). In study II, graded doses of ANP were infusion into 16 other HTs and Nts on an 8 g/day NaCl diet. ANP infusion at 2.5 ng/kg/min increased the plasma levels of ANP by 80% (p less than 0.001). Such increments were associated with an increase in urinary Na excretion by 25% (p less than 0.02) in both HTs and NTs. This rise in plasma ANP was comparable to that induced by high NaCl intake. Thus, a slight increase in plasma ANP induced by dietary Na loading seems to augment renal Na excretion, suggesting that ANP may play a physiological role in body fluid volume regulation.

Adult↗
PubMed1988

Stimulation of internal capsule, thalamic sensory nucleus (VPM) and cerebral cortex inhibited deafferentation hyperactivity provoked after gasserian ganglionectomy in cat.

Facilitation of the opiate-mediated system provides relief of excess pain but not of deafferentation pain. Influence on neuronal hyper-activity, which was provoked after the deafferentation of the peripheral trigeminal nerve (deafferentation hyperactivity; DH), by stimulation of the internal capsule (IC), VPM nucleus of the thalamus and by the cerebral sensorimotor cortex, was examined. This experiment demonstrates that a suppressive effect is exerted on the sustained neuronal hyperactivity, which was proved to have a close relationship with deafferentation pain. In the preliminary experiment, it was confirmed that DH was provoked by coagulation of unilateral (left side) Gasserian ganglion in 29 adult cats, who were allowed to survive up to 72 days. DH, sustained high amplitude discharge without any stimuli on the face or neck, was detected in the subnucleus caudalis of the spinal trigeminal nucleus (STNcd) of the denervated side. DH was never suppressed by facilitation of the opiate-mediated system. 87 of 113 neurones identified in the STNcd of the denervated side showed DH in another 18 cats. In 30 of 55 neurones examined, DH was conspicuously suppressed by the stimulation of contralateral (right) side, 11 of 29 neurones by ipsilateral IC. Five of 13 neurones were suppressed by contralateral VPM stimulation, 2 of 3 neurones by ipsilateral stimulation. Stimulation of cortical area, SM1 of MS1, in other 15 cats, considerably suppressed DH in STNcd. Microinjection of wheat-germ-agglutinin in the cerebral cortex revealed in direct projection of the descending fibre from MS1 to STNcd and brain stem reticular formation via IC.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1988

[Unruptured cerebral aneurysms in two siblings screened by cerebral computed angiotomography].

The authors report two siblings, both of whom had unruptured cerebral aneurysms found by screening examination of noninvasive cerebral computed angiotomography. Other authors have reported unruptured cerebral aneurysms detected by conventional cerebral angiography in asymptomatic relatives of families in which two or more individuals had cerebral aneurysmal rupture. It is of interest that, in our cases, the unruptured cerebral aneurysms were detected by noninvasive cerebral computed angiography in two asymptomatic siblings in a family with no history of ruptured aneurysm. To the best of our knowledge, this is the first report of detection of unruptured familial aneurysm by cerebral computed angiotomography. Case 1 is a 67-year-old female who had been complaining of dullness in the head. Cerebral computed angiotomography showed a small high density nodule, suggesting an unruptured aneurysm of the right middle cerebral artery. An aneurysm with a diameter of 4 mm was found in the right middle cerebral artery. A 72-year-old male, who was a brother of case 1, had been afraid of having cerebrovascular disease, and wanted to have a neurological examination check-up. Computed angiotomography revealed a high-density nodule in the anterior communicating artery. Conventional cerebral angiogram showed a 6 X 7 mm aneurysm. However, both of the patients refused surgical treatment. Lozano et al reviewed the previously reported familial aneurysm cases. According to them, familial aneurysm tends to rupture at a younger age and at a smaller size than non-familial aneurysm. It is well known that asymptomatic members of familial aneurysm have a risk of developing aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

[Chronic encapsulated intracerebral hematoma due to metastatic brain tumor: a case report].

Intracerebral hemorrhage from a brain tumor can mask the cause of bleeding, confuse the diagnosis, and affect the treatment and prognosis. This type of hemorrhage is generally regarded as a rapidly progressive, fulminating disease, sudden in onset, with the outcome being death or profound neurological deficits. Such hemorrhages are demonstrated by CT scan as intracerebral high density areas. Intracerebral hematomas producing chronic neurological disability and chronic intracerebral hematomas are rarely reported. We experienced a case of chronic intracerebral hematoma due to metastatic brain tumor. The patient was a 60-year-old female, and the initial symptoms were mild headache followed by right homonymous hemianopsia. The intracranial lesion was demonstrated by CT scan as an oval-shaped low density area (3 X 4.5 cm) with a ring enhancement in the left occipital lobe. MRI showed marked high intensity by short SE and long SE in the left occipital lobe. A left occipital craniotomy was performed. No tumor could be seen macroscopically except for an old encapsulated hematoma. Aspiration of the liquid hematoma and biopsy of the wall of the hematoma were done. A histological examination revealed an adenocarcinoma. Spontaneous bleeding from brain tumors was reviewed, and diagnostic problems were discussed.

Adenocarcinoma↗
PubMed1987

[Elementary components of the recto-anal reflex observed in decerebrate dogs and cats].

The electrical activities of three peri-anal muscles; internal anal sphincters, external anal sphincters and anal longitudinal muscles in decerebrate dogs and cats, were recorded by single, bipolar, macro-electrodes with identical methods, as those described by Ihara & Takahira (1984) and by Tamura & Takahira (1985). The overwhelming activity could vary in different experiments, however, the activity of internal sphincters-slow spikes, was mostly revealing in majority of experiments. The waxing and waning amplitudes of internal sphincter-slow spikes were seen in almost all records, but their waxing cycles were not synchronized between different recording foci in single animals. Further, such alteration of spike size did not directly correlate with detectable change of anal canal pressure. Rather, the waxing and waning of slow spikes seem to be due to a 'beating' of pacemaker waves, originated from multiple generators in internal sphincters. Intravenous injection of 'somatic' neuro-muscular blocking agent; suxamethonium chloride, did not cause any alteration of pressure level and of internal sphincter-slow spike rate, indicating that the anal canal pressure was primarily dependent on sustained activity of internal sphincters, not on tonic discharge of external sphincters. The graded increase of distension volume in rectum brought about progressive lengthening of inhibition of internal sphincters, in turn, causing prolongation of falling phase of pressure in the recto-anal reflex. Although the tonic discharge of external sphincters in decerebrate animals was also completely inhibited by rectal distension, this silence did not induce any significant change in anal canal pressure. It is concluded that the external sphincter is not a tonic pressure-yielding element except a transient squeeze of anal canal, instead, it is a resistive element against complete relaxation of tonic pressure-yielding internal sphincter.

Anal Canal↗
PubMed1987

Decreased dopamine level in the epileptic focus.

Catecholamine and serotonin in the focus tissues of 12 intractable epileptic patients who underwent surgery were analysed by high performance liquid chromatography with electrochemical detection, and it was found that dopamine contents in epileptic foci were clearly lower than in surrounding tissue in 7 of the 12 epileptics examined. In the other 5 patients, dopamine levels were much lower than in non-convulsive neuropathic patients.

Adolescent↗