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Biomedical subjects

T Kubo

Publications and source records attributed to T Kubo.

At least 181 records · Page 10Linked to original sources
PubMed2000

Identification, characterization and cDNA cloning of two novel proteins secreted into the external space of the regenerating leg of Periplaneta americana.

We have isolated two proteins (Rap 60 and Rap 40) that were expressed specifically in regenerating legs of the American cockroach (Periplaneta americana). These proteins appear to be derived from a precursor protein with 443 amino acid residues termed regeneration-associated protein (RAP). Rap 60 and Rap 40 corresponded to Glu 223 to Ser 443 and Glu 223 to Glu 366 of RAP, respectively. Hence, Rap 40 is the N-terminal part of Rap 60. These proteins contained 13 repeats of a novel motif, [Glu/Asp-Glu/Asp-Val/Ala-Lys]. The gene encoding RAP was shown to be expressed during embryogenesis and by newly-formed epidermal cells of regenerating legs. Rap 60 and Rap 40 were secreted into the external space of regenerating leg saccules, where they accumulated, suggesting that they are components of extracellular matrix of regenerating leg saccules.

Amino Acid Sequence↗
PubMed2000

Extracellular norepinephrine in the medial hypothalamus increases during feeding in chicks: a microdialysis study.

Norepinephrinergic function in the medial hypothalamus is important for the regulation of feeding behavior in chicks as well as in rats. This study was conducted to clarify the variation of extracellular norepinephrine (NE) in the medial hypothalamus, including the paraventricular nucleus (PVN) and the ventromedial hypothalamic nucleus (VMN), during feeding behavior of layer-type chicks. To measure extracellular NE and 4-hydroxy-3-methoxyphenylglycol (MHPG), a major metabolite of NE, we used microdialysis and high-pressure liquid chromatography (HPLC) with electrochemical detection. After the collection of baseline samples, food-deprived animals were allowed access to the food for 3 h. Extracellular NE significantly increased during the first hour of access to food, and then returned to baseline levels. MHPG also increased during the feeding, but its increase continued throughout the remainder of the experiment. This study suggests that the variation of NE in the medial hypothalamus may be involved in the control of feeding in layer-type chicks.

Animals↗
PubMed2000

Reconstruction of the anterior cruciate ligament using a double bundle.

We developed a reconstruction technique for the anterior cruciate ligament using a double bundle that is the combination of bone-tendon-bone (BTB) from the patellar tendon and semitendinosus tendon (ST). BTB is fixed in the tunnels produced on the isometric points on the tibia and femur. ST is fixed on the tibial tunnel through the same route as the BTB, but on the femur, through the over-the-top route, which is located posterolateral to the femoral tunnel. Use of this double bundle realizes a physiologically more durable reconstruction because BTB corresponds to the anteromedial bundle of the ACL and ST corresponds to the posterolateral bundle, and these produce 2 different tension patterns within the bundle. This technique is also applicable to revision surgeries for patients with an extended bone loss on the tibia.

Anterior Cruciate Ligament↗
PubMed2000

Assessment of the otolith-autonomic response using spectral analysis of the R-R interval and blood pressure.

The effects of otolith stimulation on systolic blood pressure (SBP) and R-R interval fluctuations were investigated in 12 healthy subjects and 5 patients with loss of labyrinthine function. The vestibular otolith organs were stimulated by centrifugal forces, the constant rotation of a chair fixed outside of the rotation axis on the horizontal plane. The chair was fixed along the direction of centrifugal force (eccentric rotation [ECR]) or along the tangent line (eccentric lateral rotation [ECLR]). The ECR stimulates both the utricular and saccular maculae, whereas the ECLR stimulates only the utricular maculae. Spectral analysis showed that in the healthy subjects, low-frequency SBP increased significantly during ECR but not during ECLR. There was no significant increase in low-frequency SBP in patients with labyrinthine loss. In the R-R interval analysis, however, the low- and high-frequency components did not change significantly in the healthy subjects during ECR. Our findings indicate that stimulation of the otolith maculae, especially the saccular organs, predominantly produces augmentation of the alpha-sympathetic activities rather than cardiac sympathovagal outflow to the heart.

Adult↗
PubMed2000

Effects of vestibular cerebellum lesion on motion sickness in rats.

The importance of the vestibular apparatus in the development of motion sickness is widely accepted, although the role of the vestibular cerebellum remains controversial. We examined the effects of vestibular cerebellum lesion on the development of motion sickness in rats. Rats do not vomit, but the behaviour known as "pica", the eating of non-nutritive substances, such as kaolin, can be used as an index of motion sickness. A 2 h load of hypergravity induced pica in rats, indicating that they suffered from motion sickness. Pica was induced by hypergravity load even after surgical lesion to the bilateral cerebellar flocculus or to the cerebellar vermis. We concluded that the vestibular cerebellum was not essential in the development of motion sickness in rats.

Animals↗
PubMed2000

Cholinergic influence on vestibular stimulation-induced locus coeruleus inhibition in rats.

In our previous study, caloric stimulation (CS) of the vestibular apparatus inhibited noradrenergic neuronal activity in the locus coeruleus (LC) in urethane-anaesthetized rats. Therefore, the inhibition of LC noradrenergic neurons is involved in vestibulo-autonomic responses. Since motion sickness can be cured by scopolamine, cholinergic neuron system may also be involved in vestibulo-autonomic responses. The present study examined the effects of intracerebroventricular injection of ethylcholine mustard aziridinium ion (AF64A), a presynaptic cholinergic neurotoxin, on CS-induced LC inhibition. In AF64A-treated rats, the CS-induced LC inhibition was less pronounced than in normal rats. In a subsequent series of experiments, the intravenous injection of scopolamine blocked the CS-induced LC inhibition. These findings suggest that central cholinergic neurons are associated with noradrenergic neuronal inhibition during the vestibulo-autonomic reflex.

Animals↗
PubMed2000

Effects of amygdala or hippocampus lesion on hypergravity-induced motion sickness in rats.

We examined the effects of amygdala lesion (AL) or hippocampal lesion (HL) on hypergravity-induced motion sickness in rats. Rats do not vomit, but the behavior known as pica, the eating of non-nutritive substances such as kaolin, can be used as an index of motion sickness. In the present study, hypergravity-induced kaolin intake and apomorphine-induced kaolin intake were measured before and after brain lesions. After AL, hypergravity-induced kaolin intake and the ratio of the hypergravity- to apomorphine-induced kaolin intakes were decreased. These results indicate that AL suppressed motion sickness more than pica behavior itself, suggesting that the amygdala plays an important role in the development of motion sickness in rats. Conversely, after HL, hypergravity-induced kaolin intake was increased, as was the ratio of the hypergravity- to apomorphine-induced kaolin intakes. These results indicate that HL aggravates motion sickness induced by hypergravity in rats, suggesting that the hippocampus counteracts motion sickness.

Amygdala↗
PubMed2000

Effects of pre-flocculectomy on Fos expression and NMDA receptor-mediated neural circuits in the central vestibular system after unilateral labyrinthectomy.

In this study in order to elucidate the role of the flocculus in the whole process of vestibular compensation from the very early stage to the chronic stage, we first examined unilateral labyrinthectomy (UL)-induced spontaneous nystagmus (SN), a behavioral marker of vestibular compensation, and Fos expression, a marker of neural activity, in the vestibular brainstem in pre-unilateral flocculectomized (pre-UF) rats. UL in pre-UF rats caused more severe vestibulo-ocular deficits at the very early stage than it did in floccular-intact rats. Fos expression occurred in the medial vestibular nucleus contralateral to the UL side (contra-MVe) and the prepositus hypoglossal nucleus ipsilateral to the UL side (ipsi-PrH), whereas Fos expression was never seen after UL in floccular-intact rats. Therefore, these findings suggest the UL in pre-UF rats activates the contra-MVe and ipsi-PrH neurons and causes great imbalance between intervestibular nuclear activities, inducing more severe vestibular symptoms at the very early stage than those in floccular-intact rats. Next, we observed MK801 (a specific antagonist on the NMDA receptor)-induced SN in pre-UF rats at the chronic stage after UL. MK801 administration to pre-UL rats caused reappearance of SN even 14 days after UL, while administration to floccular-intact rats at a post-UL interval of 14 days never induced decompensation. Therefore, these findings suggest that the flocculus takes part in NMDA receptor-mediated neural circuits involved in vestibular compensation and modifies the neural interactions at the chronic stage after UL. Taken together, those results suggest that the flocculus plays important roles in the restoration of a balance between intervestibular nuclear activities, to reduce vestibular symptoms during the very early stage, and thereafter in the modification of NMDA receptor-mediated neural interactions in the central vestibular system at the chronic stage.

Animals↗
PubMed2000

Phage display of xylan-binding module of xylanase J from alkaliphilic Bacillus sp. strain 41M-1.

Xylanase J from alkaliphilic Bacillus sp. strain 41M-1 has a family 11/G catalytic domain and a xylan-binding module (XBM). The XBM of xylanase J was displayed on the surface of filamentous bacteriophage. The XBM expressed on the phage surface retained binding activity to xylan. Random mutations were introduced in the XBM gene by error-prone PCR, and the repertoire was cloned for display on phage. Sequence analysis of the xylan-binding activity-deficient mutants revealed that Phe 284 and Trp317 of the XBM would contribute to the xylan-binding activity.

Bacillus↗
PubMed2000

Structure and affinity of DNA binding peptides.

Artificial peptides designed to form alpha-helical, beta-turn, antiparallel beta-sheet and beta-hairpin structures which are among the motifs most frequently found in natural DNA/RNA binding proteins were synthesized and their characteristic features were examined in the presence or absence of double or triple stranded DNA by means of UV melting experiments, CD spectra, SPR measurements. It was revealed that amphiphilic character arising from the specific secondary structures and positive charge in the hydrophobic face of peptides played an important role in the interaction with DNA, and that hybrid duplex and triplex were intensively stabilized by the cationic amphiphilic peptides. It was also found that these peptides could protect dsDNA against DNase 1 digestion. These results indicate that structurally designed amphiphilic peptides synthesized in the present study can be powerful tools for antisense and antigene strategies.

Amino Acid Sequence↗
PubMed2000

Molecular cloning and characterization of SRAM, a novel insect rel/ankyrin-family protein present in nuclei.

Previously, we purified a 59-kDa protein that binds to the kappaB motif of the Sarcophaga lectin gene. Here we report its cDNA cloning and some of its characteristics as a novel member of the Rel/Ankyrin-family. This protein, named SRAM, contained a Rel homology domain, a nuclear localization signal and 4 ankyrin repeats, but lacked the Ser-rich domain and PEST sequence that Relish contained. We found that SRAM was localized in the nuclei of NIH-Sape-4 cells, which are an embryonic cell line of Sarcophaga. The Sarcophaga lectin gene promoter containing tandem repeats of the kappaB motifs was activated in NIH-Sape-4 cells. In Drosophila mbn-2 cells, Dif alone activated this reporter gene and a cooperative effect was detected when SRAM and Dif were co-transfected, although SRAM alone did not activate it. This is the first report of a Rel/Ankyrin molecule that exists in the nuclei.

Amino Acid Sequence↗
PubMed2000

Retinoic acid accelerates the development of reproductive organs and egg production in Japanese quail (Coturnix coturnix japonica).

The effects of retinoic acid on the development of reproductive organs and egg production in female Japanese quail (Coturnix coturnix japonica) were investigated. Female quail were fed a diet containing retinoic acid at 4 mg/kg (RA) or two diets containing retinyl acetate at 5000 IU/kg (VA1) or 14 000 IU/kg (VA2) after being fed a vitamin A-free diet for 2 wk (experiment 1). The oviduct and ovary grew more rapidly (P < 0.05) in RA-treated quail than in VA-treated quail at 5 wk of age. In addition, the body weight of RA-fed quail was also greater (P: < 0.05) than that of VA-fed quail at 5 wk. The RA-treated quail laid their first eggs approximately 5 days earlier (P < 0.05) than the VA-treated quail. Furthermore, these RA-fed quail laid more eggs (P < 0.05) than those VA-fed quail during the experimental period. To confirm the results of experiment 1, a similar experiment was conducted to record the first egg and total eggs laid by quail fed VA2 or RA (experiment 2). The early onset of oviposition was again observed in the RA-treated group (P < 0.01). These results suggest that retinoic acid has a stimulating effect on the reproductive system of female Japanese quail, as has been previously shown in the reproductive system of male Japanese quail.

Animals↗
PubMed2000

A new technique for the treatment of syndactyly with osseous fusion of the distal phalanges.

In treating complex syndactyly of the hand, including bony union of varying degrees, how to cover the exposed bone surface is still disputable. The authors adopted a homemade device for the treatment of a case of syndactyly with terminal bony union. External tissue expander theory was applied to their device, and expansion of the cutaneous bridge was followed by division of the fused distal phalanges. Two months later the raw bone could be covered simply with the expanded local skin, and no skin graft was needed except for at the base of the affected fingers. This technique produces good cosmetic results of the fingertips and nail grooves without secondary deformities.

Humans↗
PubMed2000

Philtral construction by composite skin-muscle rotation and orbicularis oris muscle advancement in secondary cleft lip deformity.

The authors describe a method of philtral construction in a secondary cleft lip deformity to achieve better philtral definition and natural lip animation. The operation begins with a skin incision based on the usual design of secondary revision. Subcutaneous undermining is then performed laterally, and medially up to the line of the new philtral ridge, where the lip is divided vertically to the mucosa. A wedge-shaped flap is developed in the medial lip by dissecting from the posterior mucosal wound edge toward the cutaneous midline up to the dermis. The composite skin-muscle flap is thus elevated and rotated 90 deg on the axis of the cutaneous midline to form the philtral ridge. The orbicularis oris muscle is reapproximated in the midline by advancing the lateral orbicularis segment. The wedge-shaped flap is placed over the advanced orbicularis, and the skin is closed. Ten consecutive patients, followed for more than 6 months, were evaluated. In all patients the lip showed a well-defined philtrum with sufficient thickness and smooth continuity. Natural lip animation was also reproduced. Purportedly, the composite skin-muscle rotation provides a well-defined philtrum, and the midline approximation of the orbicularis muscle provides natural lip animation.

Adolescent↗
PubMed2000

Antithrombin III deficiency in a patient with multifocal osteonecrosis.

The authors examined a 35-year-old man who had multifocal osteonecrosis on the right and left femoral heads, left humeral head, and right scaphoid. The patient previously had a diagnosis of Type I congenital antithrombin III deficiency but had no other risk factors for osteonecrosis. This patient was thought to have systemic thromboembolism because of the increased blood coagulability resulting from antithrombin III deficiency. Thrombophilia (increased likelihood of thrombosis) and hypofibrinolysis (reduced ability to lyse thrombi) have been implicated as causative factors for osteonecrosis. This case shows a possible relationship between thrombophilic antithrombin III deficiency and multifocal osteonecrosis.

Adult↗