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Biomedical subjects

I Yamanaka

Publications and source records attributed to I Yamanaka.

At least 37 records · Page 2Linked to original sources
PubMed1998

Targeted gene transfer to corneal endothelium in vivo by electric pulse.

A novel method of in vivo targeted gene transfer to intentionally selected areas of the corneal endothelium was developed. Plasmid DNA with the lacZ gene coding for beta-galactosidase was injected into the anterior chamber of adult Wistar rats, and eight pulses of electricity at intensities ranging from 5 to 40 V/cm were delivered for 50 ms to the cornea with a specially designed electric probe in order to determine the effect of gene transfer on the corneal endothelial cells. Gene expression was visualized by enzymatic color reaction using X-gal in enucleated eyes on days 1, 3, 7, 14 and 21 after gene transfer. The treated eyes were then photographed and the X-gal-positive areas were evaluated by an image analyzer. The ratios of the areas (X-gal-positive area/area of entire corneal endothelium x 100%) were then calculated to determine gene transfection efficiency. The expression of beta-galactosidase was clearly detected in the cytoplasm of the corneal endothelial cells as early as day 1 and lasted until day 21. The most intense gene expression was observed on days 1 and 3 (5.21% on day 1 and 6.45% on day 3). The expression of beta-galactosidase on day 3 was most evident following delivery of 20 V electric pulses (0.09% at 5 V, 0.03% at 10 V, 6.45% at 20 V). beta-Galactosidase expression was limited to the corneal endothelial cells in highly selected areas and no beta-galactosidase expression was detected in any other intra- or axtraocular tissues. In addition, no cell damage was apparent in the cornea and no inflammation was detected in any other intraocular tissues. Thus, low-voltage electric pulses successfully transferred the gene of interest to highly selective areas of the corneal endothelium without inducing any pathological changes. This targeted gene transfer method appears to have great potential for use in gene therapy for ocular diseases.

Animals↗
PubMed1997

Leech extracellular hemoglobin: two globin strains that are akin to vertebrate hemoglobin alpha and beta chains.

Leech (Whitmania edentula, Haemadipsa zeylanica var. japonica and Erpobdella lineata) extracellular hemoglobins are basically composed of three constituent subunits, a dimer (D1 and D2 chains) and two monomers (M1 and M2 chains). We isolated these four chains from respective species by a combination of reversed-phase chromatography on a Resource RPC column and gel-filtration on a Superdex 75 column. The apparent molecular masses of the four globin chains were estimated by SDS-PAGE analysis to be 13 kDa (M1), 16 kDa (M2; 19 kDa in its reduced form) and about 27 kDa for the dimer subunit (13 kDa for D1; 15 kDa for D2), regardless of the source. The amino (N)-terminal segments (21-30 residues) from twelve globin chains of the above three species were determined and aligned. It was found that the twelve sequences could be separated into two distinct globin groups A and B. This finding supports the original idea of "two globin strains in annelid hemoglobin", which was proposed without any evidence for leech hemoglobins. Comparing the sequences in the three classes of Annelida, Hirudinea, Oligochaeta and Polychaeta, we found two invariant amino acids, Cys and Trp, which are interposed by eleven amino acid residues. Furthermore, the globin chains belonging to strain A were readily discernible as they had three more invariants, Ser-13, Asp-16 and Trp-28, while the globin chains of strain B had two more invariants, Lys-12 and Arg-27. Consequently, we propose that each of the three classes of Annelida have two distinct groups of globin chains that are akin to vertebrate hemoglobin alpha and beta chains.

Amino Acid Sequence↗
PubMed1997

Changes in the phosphorylation states of connexin43 in myoepithelial cells of lactating rat mammary glands.

Using specific antibodies and cDNA probe, we examined the expression pattern of a major gap junction protein, connexin43 (Cx43), in rat mammary glands during pregnancy and lactation. Double immuno-fluorescence revealed that the labeling of Cx43 was superimposed in the alpha-smooth muscle actin-positive cells, suggesting that myoepithelial cell were interconnected by gap junctions formed of Cx43. Just after delivery, the Cx43-labeled plaques were enlarged and increased in intensity. Northern and Western blot analyses confirmed the dramatic induction of Cx43 at both mRNA and protein levels on the day of parturition. Cx43 mRNA transcript immediately declined, while the increase of Cx43 protein continued for a few days. During pregnancy, immunoblots showed two bands of almost equal amounts at 43 and 45 kDa. Following delivery, the 45-kDa band gradually increased in intensity with a concomitant decrease of the 43-kDa band. From the sixth day of lactation, Cx43 was always detected as a single band at 45 kDa. Alkaline phosphatase treatment of immunoprecipitated Cx43 revealed that both bands represented phosphorylated forms, thus indicating that Cx43 was naturally phosphorylated and that it altered its phosphorylation states during lactation stages. These results suggest that the induction of Cx43 with the changes in the phosphorylation states plays an important role in the lactating function of myoepithelial cells in rat mammary glands. This is the first report on the changes of Cx43 phosphorylation states during physiological stages in vivo.

Amino Acid Sequence↗
PubMed1996

Immunohistochemistry of a cytoplasmic dynein (MAP 1C)-like molecule in rodent and human brain tissue: an example of molecular mimicry between cytoplasmic dynein and influenza A virus.

Immunohistochemistry with an antibody to influenza A/Aichi/2/68 (H3N2) virus was performed using normal mouse, rat and human brain tissues. Dot-like or filamentous structures in the neuronal cytoplasm were clearly stained. Axons were also stained, but weakly. Lewy bodies in Parkinson's disease substantia nigra were also positive. Immunoscreening of the antibody using mouse brain cDNA revealed that this antibody recognized the heavy chain of cytoplasmic dynein. Immunoblot analysis also showed that the reactive molecule was the same size as cytoplasmic dynein (microtubule-associated protein 1 C). This is an example of molecular mimicry between cytoplasmic dynein and influenza A virus, and the antibody appears to be useful for the localization on cytoplasmic dynein in the central nervous system.

Animals↗
PubMed1995

Microglial localization of alpha-interferon receptor in human brain tissues.

The localization of the alpha-interferon receptor (alpha-IFNR) was examined in human brain tissues from neurologically normal, Alzheimer's disease (AD) and cerebral infarction cases, using one antibody (IFNaR3) which preferentially recognizes alpha 2-IFN receptor and a second antibody (anti-p40) which recognizes the soluble alpha-IFN alpha/beta receptor. In all cases, microglial cells were stained with the antibodies. In infarct brains, macrophages were intensely labeled for alpha-IFNR. The anti-p40 antibody also showed capillary staining which might be due to residual blood plasma. On Western blots, IFNaR3 recognized only a 210 kDa alpha-IFN/receptor complex, indicating its localization in microglial cells. The anti-p40 antibody recognized this complex as well as four other major materials of lower molecular weight. These results suggest that alpha-IFNR protein is constitutively expressed in microglial cells.

Aged↗
PubMed1995

[Type and screen system for efficient use of blood on elective surgery].

For the efficient use of blood resources, we have adopted the Type and Screen system (T & S) and Maximum Surgical Blood Order Schedule (MSBOS) for elective operations. To evaluate the usefulness of these systems, we analyzed the crossmatched to transfused blood ratio (C/T ratio) for the period of one year before and after the adoption of the systems. C/T ratio were 4.65 and 2.38 respectively and crossmatched blood units decreased from 3799 to 2511 units. These results show the usefulness of these systems in perioperative blood transfusion system. It is possible to make use of blood more efficiently by further detailed re-evaluation of both T & S and MSBOS systems.

Blood Transfusion↗
PubMed1995

Associated movement as a sequel to thoracotomy: aberrant regeneration to the latissimus dorsi muscle.

We describe two patients with unusual associated movements as a sequel to thoracotomy. The two patients developed involuntary twitchings of the latissimus dorsi, which were induced by contractions of the adjacent muscles, the serratus anterior muscle in patient 1 and the external intercostal muscle in patient 2, after lobectomy for lung cancer. Electrophysiological and radiological studies showed that aberrant regeneration from the adjacent nerves to the denervated latissimus dorsi could be responsible for the associated movements.

Electromyography↗
PubMed1995

[Asynergia in cerebellar ataxia--the significance of impairment of elbow fixation in forearm pronation-supination test].

Patients with cerebellar ataxia often show swing of the upper arms or the elbows in forearm pronation-supination test (FPS test). Eleven healthy volunteers and sixteen patients with cerebellar ataxia were examined. We observed FPS test of the subject with their shoulder and elbow joints being flexed at a right angle respectively in sitting position, and recorded them by VTR. We noticed following four points in FPS movement: 1) velocity and regularity, 2) amplitude, 3) finger posture, 4) state of elbow fixation. We recorded surface EMG of the upper arm-fixing muscles (deltoid, pectoralis major, infraspinatus) and the forearm-moving muscles (biceps brachii, pronator teres). In controls, FPS movements were regular and speedy. The upper arm was so well fixed that the elbow did not swing. Continuous discharges were recorded from upper arm-fixing muscles when the upper arm was lifting. Reciprocal grouping discharges were recorded during FPS movements from upper arm-fixing muscles so that they were suppressing the swing of the elbow. In ataxic patients, FPS movements were dysrhythmic and slow. The elbow swung during FPS test. We observed internal rotation and abduction of the shoulder when forearm pronated, and outer rotation and adduction of the shoulder when forearm supinated. Reciprocal grouping discharges that were reverse of normal ones were recorded from upper arm-fixing muscles so that they were aggravating the swing of the elbow. Synergia is an ability to accomplish the various muscle contractions coordinately when making up a certain action. Asynergia is one of the characteristic features of disturbance of the association of muscle contractions of the upper arm and the forearm. FPS test is easy and useful to detect asynergia of the upper extremity in cerebellar ataxia.

Adult↗
PubMed1994

Immunocytochemical studies of major gap junction proteins in rat salivary glands.

We examined protein components of the gap junctions between acinar cells of the parotid, sublingual and submandibular glands of the rat, using type-specific antibodies directed against major gap junction proteins, connexin32 (Cx32) and connexin26 (Cx26). Double-immunofluorescence microscopy revealed that fluorescent spots of both connexins in the parotid and sublingual glands were distributed between the apposed regions of acinar cells. They appeared together, or were co-localized. The intensity of the Cx26-associated fluorescent signals was relatively weak in the submandibular glands compared with the other glands and was absent from some acini. When present, these spots were always co-localized with Cx32 immunoreactive positive spots. The results suggest that Cx32 and Cx26 in rat salivary glands are colocalized within the same gap junctional plaques when simultaneously expressed by the same acinar cells.

Animals↗
PubMed1993

[A case report: partial anomalous pulmonary venous return of the left lung communicating with the left atrium through the aberrant vein].

A rare case with partial anomalous pulmonary venous return was presented. The left superior pulmonary vein was drained into the left innominate vein via a common vertical vein and it also communicated with the left atrium via a small aberrant vein. All the other pulmonary veins were normally drained into the left atrium. The surgical repair was performed through the midline sternotomy. The junction of the vertical vein and the left innominate vein was ligated with slight elevation of the pressure in the left pulmonary vein. Under the cardiopulmonary bypass, the secundum atrial septal defect was closed by direct sutures. The postoperative course was uneventful and there was no pulmonary congestion in the left upper lung field.

Child↗
PubMed1993

[Severe theophylline toxicity in a pregnant asthmatic patient].

A 32 year old pregnant woman who had taken large doses of theophylline for asthmatic attack was brought to our emergency medical center with convulsion and respiratory disturbance. Serum theophylline concentration was 52 micrograms.dl-1 on admission. We intubated the patient to control convulsion and respiration and performed cesarean section. Serum theophylline concentration of the newborn was almost at the same level as that of her mother. Baby was placed on ventilator for several days and discharged without trouble. We must consider the pregnancy as a major risk factor of theophylline toxicity.

Adult↗
PubMed1992

Comparative study of magnetic resonance and CT scan imaging in cases of severe head injury.

The distribution, frequency, and appearance of head injuries were evaluated with MRI and CT in a prospective study of 155 patients with acute (n = 124) and chronic (n = 31) head injuries. MRI was significantly more sensitive than CT in the detection of intraaxial injury at any stage. In severe cases, central structure lesions were detected in approximately 80% of patients. Severity on admission was compatible with MR findings. However it was difficult to decide on neurobehavioural prognosis from initial MRI findings only.

Adolescent↗
PubMed1990

["Acro-erythro-cyanosis"--peculiar vasomotor symptoms due to cervical hernial myelopathy].

Two cases of cervical myelopathy, which exhibited peculiar vasomotor symptoms ("acro-erythro-cyanosis") on distal regions of the four limbs are reported. Continuous reddening, swelling and skin temperature increase were observed on both hands and feet in case 1, a-44-year-old man, and on both hands in case 2, a-47-year-old man. Cold stimulation resulted in cyanosis and decrease of skin temperature on the affected regions paroxysmally. The condition of skin at room temperature may be caused by arteriectasia of arterioles due to hypotonia of vasomotor fibers, and this was similar to erythromelalgia. On the other hand, cold stimulation may have led to this condition, where the contraction of skin arterioles due to hypertonia of vasomotor fibers was added to the dilation of venule, and this was similar to acrocyanosis. Consequently, we provisionally named the vasomotor symptoms in the present cases as "acro-erythro-cyanosis". The other neurological signs were as follows. Case 1: mild weakness in right upper and lower limbs and left small hand muscles, mild superficial and deep sensory disturbance on bilateral palms and soles and decrease of vibration on bilateral lumbar regions and thereunder. Case 2: mild weakness of right small hand muscles, superficial sensory disturbance on distal regions of bilateral upper and lower limbs and a decrease of joint position sense on right hand. Myelography and metrizamide CT myelography revealed a high-degree deformity of the spinal cord due to the herniated disks between C4 and C5 in case 1 and between C3 and C4 in case 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗