The effect of the floor plate on pattern and polarity in the developing central nervous system.

The effect of floor plate on cellular differentiation in the neural tube of quail embryos was examined. In the developing neural tube the floor plate, which consists of specialized neuroepithelial cells, is located in the ventral midline of the neural tube. When Hensen's node was extirpated the floor plate and notochord did not develop, and the normal differentiation of the ventral horn motor neurons and dorsal and ventral roots did not occur. When one side of the neural tube was deprived of notochord, the ventro-dorsal differentiation took place on both sides. However, when one side of the neural tube was deprived of the floor plate, the ventral horn motor neurons and dorsal and ventral roots did not develop on that side. These observations suggest that the floor plate influences motor neuron differentiation and acts as an intrinsic organizer to establish pattern and polarity in the developing nervous system.

Effects of pharmacological lesion of the nucleus retroambiguus region on the pharyngeal phase of swallowing.

Pharyngeal swallowing is controlled by synaptic interactions within a swallowing central pattern generator (sw-CPG) that is composed of a dorsal and a ventral swallowing group (VSG). Here, we used electrical stimulation (10 s) of the superior laryngeal nerve (SLN; 20 Hz; pulse width: 100 µs) to explore the role of the VSG in an arterially-perfused brainstem preparation of rats. To investigate the effects of pharmacological lesion (local microinjection of an GABA(A)-R agonist) of the nucleus retroambiguus (NRA), a designated component of the VSG, we recorded phrenic (PNA) and vagal nerve (VNA) activities. Control SLN stimulation with stepwise increasing stimulus intensities (from 20 µA to 160 µA) elicited robust suppression of PNA and evoked sequential swallowing activity in the VNA. Lesioning of the NRA had no effect on the pattern of pharyngeal swallowing, but significantly increased the sensory gating of SLN inputs. We conclude that the NRA is not part of the VSG, but appears to have important roles for the central gating of swallowing.

Catecholamine-induced ductus arteriosus constriction in children.

Our data suggest that the vascular smooth muscle of the PDA remains capable of constriction beyond a patient's infancy, at least at the pulmonary end. In some cases of PDA, catecholamines may induce late closure.

Postoperative bronchopleural fistula: clinical and experimental study.

It is a well-known fact that in pulmonary tuberculosis patients treated by resection, the quality of the suture material used for closing the bronchial stump plays an important role in the pathogenesis of postoperative bronchopleural fistula. Of 426 cases treated surgically and in whom silk suture thread was used, 23 developed bronchopleural fistula, whereas none of the 220 cases sutured with nylon monofilament developed abnormality. Statistical analysis of 100 surgical cases with silk thread suture and of 100 cases with nylon monofilament suture showed that the two groups had no marked differences as to background factors. Howevers, as compared with the silk-thread suture group, the nylon-monofilament suture group revealed more consistently favorable postoperative bronchoscopic findings. Experimental studies with dogs showed a similar lack of complications when the monofilament suture material was used, as contrasted were conducted in hospital by the same surgical personnel using the same procedures, it can be said that, to insure prevention of complications, the suture material for bronchial stump closure should be of non-irritating nature and preferably of monofilament strength and quality, such as nylon monofilament.

Observations on the early development of the dorsal root ganglia and ventral root in quail embryos.

Early development of the dorsal root ganglia and ventral roots in quail embryos was observed by using HNK-1 antibodies. The dorsal root ganglia showed a dumbbell form in the horizontal plane, i.e. one dorsal root ganglion was constituted by two groups arranged craniocaudally. These observations suggest that the complex form of the dorsal root ganglia is brought about by a subsegmentation of the neutral tube and peripheral nerve supply. Further, it was observed that the segmental boundaries of the neural tube, which were indicated by the individual ventral roots, differed from the boundaries indicated by mesodermal segmentation. These findings seem to provide us with a new viewpoint for analyzing the nervous system.

Biosystematic studies on the family Tofieldiaceae I. Phylogeny and circumscription of the family inferred from DNA sequences of matK and rbcL.

In order to specify phylogenetic positions of the genera of Tofieldiaceae (Tofieldia, Triantha, Pleea, Harperocallis, Isidrogalvia), and to suggest reasonable circumscription of the family and genera of Tofieldiaceae, we determined DNA sequences of matK and rbcL for each genus of the family, and analyzed them phylogenetically with the 45 families and 113 genera of the monocots other than Tofieldiaceae, whose matK and rbcL sequences have already been reported. We found that Tofieldia, Triantha, Pleea, and Harperocallis form the same clade, which receives 100% bootstrap support. This clade can be regarded as corresponding to Tofieldiaceae, and is embedded in the clade of Alismatales (98%). On the other hand, Isidrogalvia is not included in this Tofieldiaceae clade, and positioned as sister to Narthecium (100%), embedded in the clade of Nartheciaceae (Dioscoreales) (100%). In the Tofieldiaceae, Pleea first diverges from the remaining three genera (100%), and then, Harperocallis diverges from the Tofieldia- Triantha complex (100%). In the Tofieldia- Triantha complex, five Tofieldia species form the same clade (100%), and two Triantha species form another clade (100%). Thus, Isidrogalvia should be transferred from Tofieldiaceae to Nartheciaceae. As Isidrogalvia, as well as the Nartheciaceae, have the carpels that are fully connate into a single style, Isidrogalvia fits the Nartheciaceae well with respect to carpel connation. After this transfer, the Tofieldiaceae correspond mainly to plants with almost free carpels and three styles. Pleea is better treated as an independent genus than included in Tofieldia. Triantha can be treated either as an independent genus or as congeneric with Tofieldia.

A simple objective parameter for perfusion study of renal transplant.

We proposed a simple parameter, the kidney-to-aorta ratio (KAR), for evaluation of renal transplant perfusion. KAR was calculated from the peak counts of the kidney and the aorta. The calculated values were compared with the visual interpretation of the radionuclide first-pass flow study, percent renal uptake (%RU), and tubular extraction rate (TER) by Bubeck's one point sampling method in 37 studies. KAR correlated well with the visual interpretation of the flow study and the other quantitative parameters. Representative cases, which showed the usefulness of KAR for the objective assessment of the perfusion status of renal transplants, were presented. In conclusion, KAR is a simple and practically useful parameter for objective evaluation and follow-up of renal transplant perfusion.

[Retrocollis and oculogyric crisis in association with bilateral putaminal hemorrhages].

A 50-year-old man with a history of hypertension developed right hemiparesis in February, 1985. Four years later, he noted tremor and involuntary extension of the neck (retrocollis) which was aggravated by walking or emotional stimuli. In addition to retrocollis, which was most pronounced upon turning the head to the left or backward, there also was upward deviation of the eyes (oculogyric crisis) and contraction of the left orbicularis oculi muscle. Magnetic resonance imaging study revealed one small old hematoma in the left posterior putamen and two in the right lenticular nucleus (one in the posterior putamen and the other in the globus pallidus). The findings in this case and in other reported cases of symptomatic retrocollis suggest that bilateral lesions of the putamen are associated with this type of focal dystonia.

[A case of fibromuscular dysplasia presenting with Wallenberg syndrome, and developing a giant aneurysm of the internal carotid artery in the cavernous sinus].

A 25-year-old man developed Wallenberg syndrome (WS). At that time his carotid angiography was normal. When he was 28 years old, he suffered from retinal artery embolism in the left eye. At the age of 30 years, he had an acute onset of abducens nerve palsy in his right eye. The carotid angiography showed a giant aneurysm at the cavernous sinus portion in the right internal carotid artery. At his age of 38, the right oculomotor, trochlear and trigeminal nerves were involved. A vertebral angiography revealed a bead-like formation, and a diagnosis of fibromuscular dysplasia (FMD) was made. An intensive angiographic examination revealed many stenotic or dilated lesions in the carotid, vertebral, coronary, renal, and hepatic arteries. A sural nerve biopsy specimen revealed that the sural vein was involved. In Japan only one case of FMD presenting with WS is known. FMD should be under consideration as an underlying disease, when WS occurred in younger patients with few risk factors. In this patient an angiography revealed no abnormality in the cavernous sinus portion of the internal carotid artery, when he suffered from WS. However, eight years later he was proved to have a giant aneurysm in the cavernous sinus portion. In conclusion, we support the hypothesis that aneurysm may originate from angiographically normal arterial wall in FMD.

[Parkinsonism, depression and akathisia induced by flunarizine, a calcium entry blockade--report of 31 cases].

Flunarizine hydrochloride (FZ), a calcium entry blockade, has been used nationwide in Japan as a cerebral active vasodilator since October, 1984. The present paper reports 31 cases of FZ-induced Parkinsonism, depression and akathisia, referred to our hospital between October 1986 and September 1988. Out of the 31 patients, four including two with Parkinson's disease and one each with progressive supranuclear palsy and olivopontocerebellar atrophy showed worsening of their parkinsonian symptoms within a few months after FZ administration. The remaining 27 patients (7 males and 20 females) newly developed Parkinsonism after treatment with FZ. Symptoms appeared one week to two years (mean: 6.1 months) after starting FZ of a daily dose of 10 mg. FZ had been used in 6 patients for cerebrovascular episodes confirmed by clinical history or brain CT, and in the remainder, for dizziness, light-headedness, hypertension, amnesia or hypochondric neurotic complaints. Akinesia and bradykinesia progressed rather rapidly after onset, and patients became unambulatory within several months. Symptoms had worsened, and L-dopa, anticholinergic drugs, and bromocriptine had been ineffective until FZ was discontinued. Their Parkinsonism was characterized by marked akinesia, bradykinesia, and moderate rigidity. Masked face was seen in most of them. Tremor was absent at rest, and induced in 12 patients by posture and/or action. Sixteen patients were accompanied by depression, and five, by akathisia. Improvement began several weeks after withdrawal of FZ, and most patients recovered almost completely within a few months although mild rigidity and bradykinesia remained in some.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pure word deafness after cerebral hemorrhage in the left temporal lobe: a case report].

We report a patient with pure word deafness after subcortical hemorrhage in the left temporal lobe. Repetition and auditory comprehension were severely impaired, while reading and visual comprehension of the same material were almost normal. He did not show hearing loss, but speech discrimination and melody recognition was poor. On the speech discrimination test, his score was low especially in the right ear. The threshold on the directional hearing test was mildly elevated. There was no temporal summation by click sounds. CT and MRI disclosed a subcortical hematoma in the left superior temporal gyrus. PET demonstrated hypoperfusion in the surrounding area, which was not activated by hearing a story. It was considered that pure word deafness in this case was due to the interruption of auditory inputs to Wernicke's area from both hemisphere by the hematoma. After 5 months, auditory comprehension recovered so that he did not have difficulty in conversation. Speech discrimination improved in both ears, probably due to the recovery of two auditory pathways; the ipsilateral pathway through the left auditory radiation and the contralateral pathway through the right auditory radiation and the corpus callosum. This case suggests that in pure word deafness due to a unilateral lesion, the improvement in speech discrimination during follow-up period may provide a clue as to the site of the responsible lesion and its recovery.

[Somatic mosaicism of p(CTG)n expansion in a case of myotonic dystrophy with parotid tumor].

Myotonic dystrophy (MD) is an autosomal dominant systemic disorder with an unstable expansion of the CTG triplet repeat in the 3'-untranslated region of the gene encoding myotonine protein kinase (DMPK) which maps to chromosome 19q13.3. Somatic mosaicism of CTG repeats in MD has been reported; and it has been observed that CTG repeats in tumor tissues associated with MD are more expanded than the other tissues. It is not rare that parotid tumors are found in patients with MD. We performed Southern blot analysis for tissues from the parotid tumor, the normal parotid gland, the skeletal muscles, and the leukocyte from a 60-year-old patient with MD. CTG repeat was most expanded in the parotid tumor, and the normal parotid gland had longer expansion of CTG repeat than the skeletal muscles. The leukocyte had the shortest expansion of CTG repeat. The expansion of CTG repeat in the parotid tumor may be related to active cell division and may underlie the occurrence of tumors in MD.

[Application of measuring 99mTc-MAG3 plasma clearance based on one-compartment model (MPC method) to renal transplantation].

Measurement of 99mTc-MAG3 plasma clearance (CLmag) based on one-compartment model (MPC method) was applied to renal transplantation and evaluated for the factors which might affect the calculated results, especially concerning renal depth. Correlation coefficient of CLmag between MPC method using real renal depth and Russell or Bubeck single sampling method was good (r = 0.852 or 0.876, respectively). Regression equation between MPC method and Russell method was y = 1.044x - 3.0 and was more closer to y = x than that between MPC method and Bubeck method. CLmag of MPC method calculated by estimated renal depth from the abdominal thickness was also similar to that by real renal depth. Even if the fixed renal depth, 4 cm, was applied, the coefficient and regression equation between MPC method and Russell method were r = 0.884 and y = 1.004x - 10.2. In conclusion, MPC method is applicable to the evaluation of renal transplants. Though measuring renal depth is best, calculation with fixed renal depth of 4 cm might be practically acceptable.

[Congenital tracheal stenosis due to complete cartilage rings with right pulmonary agenesis].

A 2-month-old male infant with severe dyspnea was diagnosed as having right pulmonary agenesis at birth and was admitted to our hospital after tracheal intubation with an endotracheal tube of 3 mm in diameter. However, the trachea was too stenotic to place the tube in the proper position. Chest X-ray on admission showed pneumonia of the left lung. Preoperative chest computed tomography (CT) scan and bronchoscopy showed that from the level of 12 mm beneath the coricoid cartilage, the trachea tapered and continuing to the tracheal carina and that the smallest tracheal level was located 18 mm distal from the coricoid cartilage, the area of which was 4 mm2. His respiratory condition rapidly deteriorated in spite of intravenous administration of antibiotics and mechanical ventilation. Percutaneous cardiopulmonary support (PCPS) was used to maintain his pulmonary function, and pericardial tracheoplasty was performed. Chest X-ray immediately after the operation did not show left lung reexpansion due to severe pulmonary edema. High-dose steroid pulse therapy was performed, but it was not effective. He died from acute respiratory failure due to infantile respiratory distress syndrome (IRDS) on postoperative day 3. The outcome in this case shows that it is very risky to repair tracheal stenosis in a patient with pneumonia using PCPS.

[Comparison between continuous intravenous and oral administration of 5-FU with LV].

UNLABELLED: In case of 5-fluorouracil (5-FU)/leucovorin (LV) treatment, which is one of the most effective forms of chemotherapy for colorectal carcinoma, 5-FU is usually continuously infused from the venous route. However, since this continuous infusion limits the patients' active daily life, oral administration is preferable. In the present study, we evaluated the efficacy and side effects of orally administered 5-FU/LV. MATERIAL AND METHODS: In the continuous intravenous infusion group (civ group), colon 26 bearing mice were cannulated into central vein from external jugular vein. From this route, either 5, 10, or 20 mg/kg of 5-FU was continuously infused for 7 days (n = 6). In another group, either 10, 20, 40 mg/kg of 5-FU was infused orally (po group, n = 6). The other 6 animals were used for the non-treatment group. In the next series, 100 mg/kg of LV was added for each group above. Tumor volume, thymidylate synthase inhibition rate (TSIR) and body weight were measured at the end of infusion. During the experimental period, mice had free access to chow and water. RESULTS: The tumor/control (T/C) volumes ratio showed that approximately twice the orally administered 5-FU dose had an anti-tumor effect equal to that of 5-FU administered intravenously. Synergic antitumor effects by LV were only revealed in the civ group. Significant body weight loss was recognized only in the po group at a 5-FU dose of more than 20 mg/kg. In summary, since the modulation effect of LV was recognized only with continuously intravenous infusion of 5-FU, further improvement of oral administration is required in the LV/5-FU combination therapy.