PubMed Health⌕ Search

Biomedical subjects

K Kuroki

Publications and source records attributed to K Kuroki.

At least 73 records · Page 4Linked to original sources
PubMed1994

A cell surface protein that binds avian hepatitis B virus particles.

We have identified a 180-kDa cellular glycoprotein (gp180) that binds with high affinity to duck hepatitis B virus (DHBV) particles. The protein was detected by coprecipitating labeled duck hepatocyte proteins with virions or recombinant DHBV envelope proteins, using nonneutralizing monoclonal antibodies to the virion envelope. Binding of gp180 requires only the pre-S region of the viral large envelope protein, since recombinant fusion proteins bearing only this region efficiently coprecipitate gp180. The DHBV-gp180 interaction is blocked by two independent neutralizing monoclonal antibodies. The protein is found on both internal and surface membranes of the cell, and the species distribution of gp180 binding activity mirrors the known host range of DHBV infection. Functional gp180 is expressed in a wide variety of tissues in susceptible ducks.

Animals↗
PubMed1994

[CT & MRI findings of refractory vasculitis].

We described CT and MRI findings of various refractory vasculitis. Refractory vasculitis must be divided into two categories including one group with major vascular involvement and another one with small or microvascular involvement. In cases with major vessel involvement such as Takayasu's arteritis, Kawasaki disease or vasculo-Behçet disease, CT and MRI depicted direct findings of vessels itself including stenosis, obstruction, aneurysm, and wall thickening. On the other hand, CT and MRI showed various extravascular findings in cases with small or microvascular involvement, such as CNS involvement in collagen vascular disease, pulmonary lesions in Wegener's granulomatosis and Churg-Strauss syndrome, and peritoneal lesion in SLE. Our results suggest that CT and MRI findings reflect various vascular condition of refractory vasculitis and correspond to various pathology.

Humans↗
PubMed1994

[Two cases of traumatic intracerebral pneumocephalus].

Two cases of traumatic intracerebral pneumocephalus, a rare complication of head trauma, are presented. Case 1: A 14-year-old boy had a strong concussion in his forehead due to a motorbike accident. Slightly obtunded on admission showing GCS 10, he became conscious in several days. Head CT performed after 17 days showed a round air image in the right frontal lobe which kept increasing in size thereafter. Bilateral frontal craniotomy was performed 31 days after the injury. A craniodural defect with a herniated brain was found in the superior wall of the posterior ethmoid sinus and repaired. Case 2: A 55-year-old man received a left forehead concussion when his motorbike ran into a car from behind. Although he had been conscious ever since admission, head CT after 15 days showed a round air image in the left frontal lobe. MRI demonstrated the air to be located in the cerebral parenchyma distinctly and the brain to have herniated into the frontal sinus. As the air showed a tendency to increase in volume and mild psychic and memory disturbances appeared, bilateral frontal craniotomy was performed 34 days after the injury. A craniodural defect with a herniated brain was detected in the posterior wall of the frontal sinus and repaired. These two patients showed a small amount of cerebrospinal fluid (CSF) rhinorrhea before the operation. Following the surgical repair, no recurrence of pneumocephalus and CSF rhinorrhea has been seen in either case. Intracerebral pneumocephalus secondary to closed head trauma was thought to have been due to herniation of contused brain into a craniodural defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

[A case of brain abscess of the basal ganglia which resulted in disastrous outcome due to ventricular ruptures].

A case of deep-seated brain abscess that ruptured twice into the ventricle and resulted in death is presented. A 45-year-old man had experienced pyrexia and headache for 3 days before admission. On admission he was somnolent (GCS: 13) but there were no abnormal neurological findings except nuchal rigidity and Kernig's sign. Computed tomography (CT) scan showed a ring enhanced mass near the left caudate head and dilated ventricles. In comparison with CT performed at the former hospital it was diagnosed that a rupture into the ventricle of the brain abscess had occurred. Ventricular drainage was performed at once and white purulent cerebrospinal fluid was obtained. Thereafter, he was treated with some antibiotics and his conditions seemed to stabilize for a while. Serial CT images demonstrated that the size of the abscess seemed to be enlarging. Just when we planned to undertake stereotactic aspiration, the second ventricular rupture occurred and he died. According to this case, it is suggested that once a deep-seated brain abscess near the ventricular system is suspected, it should be aspirated by means of CT-guided stereotactic surgery immediately.

Basal Ganglia Diseases↗
PubMed1993

[Effects of sevoflurane on spinal dorsal horn WDR neuronal activity in cats].

The effects of sevoflurane (S) (0.5%, 1.5%, and 2.5%) on the spinal dorsal horn wide dynamic range (WDR) neuronal activity were studied in either spinal cord intact or spinal cord transected cats. Extracellular activity was recorded in the dorsal horn from single WDR neurons responding to noxious and non-noxious stimuli applied to the cutaneous receptive fields on the left hind paw foot pads of intact or decerebrate and spinal cord transsected (L1-2) cats. When BK 10 micrograms was injected into the femoral artery ipsilateral to the recording site as the noxious test stimulus in the spinal cat, 7 of 8 WDR neurons gave excitatory responses which were not depressed by sevoflurane 0.5% and 1.5% but were depressed significantly by 2.5%. On the other hand, when BK 10 micrograms was injected into the femoral artery ipsilateral to the recording site in the intact cat, 6 of 13 WDR neurons (46%) gave excitatory responses, which were significantly depressed by sevoflurane 0.5%, 1.5% and 2.5%, and 7 of 13 WDR neurons (54%) gave inhibitory responses, which were significantly depressed sevoflurane at 0.5%, 1.5%, and 2.5%. In conclusion, we have found that sevoflurane reduces the excitation as well as the inhibition of dorsal horn WDR neuronal activity induced by BK injection.

Animals↗
PubMed1992

Multiple metastatic calcifications detected by bone scintigraphy and demonstrated by CT.

Metastatic calcifications according to histopathologic and scintigraphic findings have been well-defined. The authors report a postoperative case of hyperparathyroidism with multiple metastatic calcifications in the lung, kidney, stomach, heart, and vessels that were primarily detected by bone scintigraphy and demonstrated by CT. Tc-99m MDP bone scintigraphy showed a markedly increased accumulation of radioactivity diffusely throughout the lung, left ventricular wall, both kidneys, and the gastric cardia and body. In the lung, plain films showed almost normal lung. CT, however, demonstrated patchy, slightly increased densities in the lung bilaterally. Cardiac CT indicated a considerably increased density of the ventricular myocardium and remarkable calcification in or near the atrioventricular septum or annulus fibrosus. Upper abdominal CT demonstrated increased densities diffusely throughout the gastric mucosa and renal cortex. Only vascular calcifications were depicted by plain films. Using both bone scintigraphy and CT provides accurate information about each lesion and each tissue, allowing precise diagnosis of even a questionable lesion in the early stage of metastatic calcification. Early diagnosis and early therapy offer the best chance for cure or palliative therapy.

Bone and Bones↗
PubMed1990

Epitope mapping of the PreS1 domain of the hepatitis B virus large surface protein.

The large (L) surface glycoprotein of hepatitis B virus is an important component of the virion envelope derived from translation initiation at the 5' end of the PreS1 domain of the surface antigen open reading frame. Since key roles in virion assembly and infectivity have been postulated for this protein, further understanding of its structure and topology is important. To this end we have mapped the epitopes recognized by a panel of monoclonal antibodies specific for this polypeptide by examining their reactivity with a series of deletion mutants of the PreS1 region expressed in cultured cells. On the basis of this and other techniques, the antibodies fall into two groups mapping to two distinct epitopes spanning residues 27-35 and 72-78, respectively. Immunoprecipitation studies indicate that both regions are exposed on the surface of HBV-encoded particles.

Antibodies, Monoclonal↗
PubMed1989

Novel N-terminal amino acid sequence required for retention of a hepatitis B virus glycoprotein in the endoplasmic reticulum.

The preS1 surface glycoprotein of hepatitis B virus is targeted to the endoplasmic reticulum (ER) and is retained in this organelle when expressed in the absence of other viral gene products. The protein is also acylated at its N terminus with myristic acid. Sequences responsible for its ER retention have been identified through examination of mutants bearing lesions in the preS1 coding region. These studies reveal that such sequences map to the N terminus of the molecule, between residues 6 and 19. Molecules in which this region was present remained in the ER; those in which it had been deleted were secreted from the cell. Although all deletions which allowed efficient secretion also impaired acylation of the polypeptide, myristylation alone was not sufficient for ER retention: point mutations which eliminated myristylation did not lead to secretion. These data indicate that an essential element for ER retention resides in a 14-amino-acid sequence that is unrelated to previously described ER retention signals.

Amino Acid Sequence↗
PubMed1989

[Individual growth study of the effects of chin cap force to the mandible].

This study was undertaken to investigate a certain regulation of the chin cap force to a growing human mandible, especially with regard to the effect on the growth amount and timing by means of allometric relation between stature and craniofacial complex. Materials were consisted of roentgencephalograms which had been taken from fifteen Japanese females with skeletal class III malocclusion and records of time length of chin cap use and stature. The results were as follows: 1. Chin cap had a great influence on mandible during the preadolescent and adolescent periods (P less than 0.01). 2. What was most influenced by orthopedic force was intercondylar width, followed by mandibular length, intergonial width, mandibular body length, and ramus height. 3. Restraint of growth was found in mandibular length, mandibular body length, and ramus height, but on the other hand acceleration of growth in intercondylar width and intergonial width was also found. In conclusion, it would be possible to say that if it is used propertly, chin cap therapy can be effective within certain limits for skeletal class III malocclusions in view of restraint and acceleration of mandibular growth.

Cephalometry↗
PubMed1988

Molecular cloning and expression of a gene for a factor which stabilizes formation of inhibitor-mitochondrial ATPase complex from Saccharomyces cerevisiae.

Stabilizing factor, a 9 kDa protein, stabilizes and facilitates formation of the complex between mitochondrial ATP synthase and its intrinsic inhibitor protein. A clone containing the gene encoding the 9 kDa protein was selected from a yeast genomic library to determine the structure of its precursor protein. As deduced from the nucleotide sequence, the precursor of the yeast 9 kDa stabilizing factor contains 86 amino acid residues and has a molecular weight of 10,062. From the predicted sequence we infer that the stabilizing factor precursor contains a presequence of 23 amino acid residues at its amino terminus. We also used S1 mapping to determine the initiation site of transcription under glucose-repressed or derepressed conditions. These experiments suggest that transcription of this gene starts at three different sites and that only one of them is not affected by the presence of glucose.

Adaptor Proteins, Signal Transducing↗