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K Koga

Publications and source records attributed to K Koga.

At least 235 records · Page 13Linked to original sources
PubMed1988

Methionine-90-spin-labeled bovine alpha-lactalbumin: electron spin resonance and NMR distance measurements.

The unique methionine residue of bovine alpha-lactalbumin was modified by irreversible alkylation with the bromoacetamido nitroxide spin-label 4-(2-bromoacetamido)-2,2,6,6-tetramethylpiperidine-N-oxyl. The line shape of the electron spin resonance (ESR) spectrum was indicative of a fairly mobile spin-label and was sensitive to the calcium-induced conformational change. Paramagnetic broadening of the spin-label ESR lines by a Gd(III) ion substituted at the high-affinity calcium site of the protein yielded a distance between the spin-label and the metal-binding site of 8.0 +/- 1.0 A. The extent of the paramagnetic line broadening by the covalently attached nitroxide spin-label on the proton resonances of several amino acid residues of the protein at 500 MHz allowed estimation of intramolecular distances between the methionine-90 residue and several resolvable protons.

Animals↗
PubMed1988

Age factor relevant to the development of radiation pneumonitis in radiotherapy of lung cancer.

The significance of age factor for the development of radiation pneumonitis is evaluated in 62 patients with lung cancer between 1977 and 1985. The younger group consists of those less than 70 years old and the elderly group of those 70 years old or more. Radiation doses ranged from 1.5 to 2 Gy, 3 to 5 times per week, therefore the delivered doses were converted to nominal single doses (rets dose). Severe radiation pneumonitis was more often observed in the elderly than in the younger regardless of radiation field size and chemotherapy (n.s.). The onset of radiation pneumonitis occurred earlier in a field size of 90 sq cm or more than in that of less than 90 sq cm in both age groups; there was no significant difference between the two age groups in each field size. The pneumonitis was more frequently noted with increasing rets dose in both age groups (n.s.) regardless of field size and chemotherapy. It is concluded that there is no significant difference in the development of radiation pneumonitis between the younger group and the elderly group, but the pneumonitis is inclined to be more severe in the latter.

Adult↗
PubMed1988

Responses in muscle sympathetic activity to acute hypoxia in humans.

Responses in muscle sympathetic activity (MSA) to acute hypoxia were studied in 13 healthy male subjects under hypobaric hypoxic conditions at a simulated altitude of 4,000, 5,000, and 6,000 m. Efferent postganglionic MSA was recorded directly with a tungsten microelectrode inserted percutaneously into the tibial nerve. Heart rate (HR) and respiratory rate (RR) were counted respectively from the R wave of an electrocardiogram and from the respiratory tracing recorded by the strain-gauge method. The average values of the MSA burst rate and total activity of MSA (burst rate x mean burst amplitude) at 4,000, 5,000, and 6,000 m were 36.4 +/- 2.6, 39.1 +/- 3.1, and 40.2 +/- 4.2 (SE) bursts/min and 616 +/- 138, 794 +/- 190, and 764 +/- 227 arbitrary units, respectively. These values were significantly higher than the values of 27.1 +/- 2.9 bursts/min and 446 +/- 28 at sea level. HR increased significantly at altitudes, but RR did not show significant change. Under severe hypoxic conditions beyond 5,000 m, there were large interindividual differences in the MSA responsiveness to hypoxia. The results indicate that MSA is activated under hypoxia by stimulating the chemoreceptors. However, the central controlling mechanisms that would be affected by hypoxia may also influence the MSA responsiveness under severe hypoxia.

Adult↗
PubMed1988

Immunological study on association between mumps and infantile unilateral deafness.

The incidence of unilateral deafness in primary school children has been reported to be about 0.1%, but the cause of most of these cases has not been clarified, because parents and children themselves cannot recognize the onset of hearing loss occurring in one ear alone. This study was performed to clarify the possibility that mumps causes infantile unilateral deafness. The results were: 1) on dividing a total of 78 cases of infantile unilateral deafness according to age from 3 to 6 years, mumps infection rate in the 4-year-old group was nearly twice that in a randomly selected group; 2) on checking the neutralizing or ELISA IgG test of 31 cases with no history of mumps only, the 4-year-old group demonstrated a positive reaction to mumps more than the randomly selected group did. The above results suggested that unilateral deafness may be caused by asymptomatic mumps infection. To confirm this, we studied 5 infantile cases of sudden hearing loss by means of ELISA IgM antibody test and found a bilateral sudden deafness in children aged 1.9 years, caused by asymptomatic mumps infection.

Antibodies, Viral↗
PubMed1988

[Long-term survivors in patients with esophageal cancer treated with radiation].

Of 80 patients with esophageal cancer treated with radiotherapy alone or in combination with chemotherapy during the past 8 years, 5 patients have survived for more than three years. Their X-ray findings revealed that of these cancers were the serrated type, 1 a tumorous type, 1 a spiral type, and 1 a funnel type. The sites of the primary tumor were Im in 3, Ei Im in 1, and Ei in 1. The length of the primary tumor ranged from 3 to 5 cm. The given radiation dose was 50 to 70 Gy. Our findings suggest that in such cases where the tumor length is 5 cm or less, that cancers sited in the Im or Ei regions and of the radiological serrated or tumorous type are candidates for curative irradiation.

Aged↗
PubMed1988

[Correlation between abnormal SSEP and clinicoradiological findings in cervical lesions].

The purpose of this paper is to evaluate the short latency somatosensory evoked potentials (SSEP) in the diagnosis of cervical lesions. Recordings were obtained from 59 patients with cervical lesions which included 24 cases of cervical spondylosis, 4 cases of disc herniation, 14 cases of OPLL, 4 cases of intramedullary tumor, 7 cases of extramedullary tumor and 6 cases of syringomyelia. SSEP changes in these cases were classified into three major types as follows: type I; normal SSEP, type II; prolongation of interpeak latency, and type III; absence of the component of SSEP. Types II and III were subdivided into two subgroups, respectively, as follows: type IIa; prolongation of interpeak latency between P9 and P11, type IIb; prolongation of P11-P13, type IIIa; no responses after P11 and type IIIb; no responses after P13. Type I was detected in 25 cases (42%), type II in 16 cases (27%), and type III in 18 cases (31%). These SSEP findings were compared with clinicoradiological findings. In type I, the locations of the lesions confirmed by the radiological findings were variable, and there was no definite tendency in the localizations. 80% of type I showed only numbness of extremities or disturbance of the superficial sensations. The cervical lesion was located just under the C5 vertebral level in type IIa and IIIa, while the lesion was extended above the C4 vertebral level in type IIb and IIIb. These results were explained by the generation sites of P11 and P13 (P11 originated from the lower dorsal column, and P13 from nearby the dorsal column nucleus).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Western-blotting method for detecting antibodies against human muscle contractile proteins in myositis.

Many investigators report anti-muscle antibodies using various kinds of methods. The Western-blotting method, however, has not previously been used for this purpose. We have detected antibodies to muscle contractile proteins in sera from patients with collagen disease and muscular dystrophy by this method. The antigens detected included myosin heavy and light chains, tropomyosin and troponin complex. Our method is a quick and sensitive way to determine which are the antigenic muscle contractile proteins.

Actins↗
PubMed1987

High-resolution proton and laser photochemically induced dynamic nuclear polarization NMR studies of cation binding to bovine alpha-lactalbumin.

alpha-Lactalbumin (alpha-LA) is a calcium binding protein that also binds Mn(II), lanthanide ions, A1(III), Zn(II), Co(II). The structural implications of cation binding were studied by high-resolution proton (200 MHz) NMR and photochemically induced dynamic nuclear polarization (CIDNP) spectroscopy. Marked changes were observed in the NMR spectra of the apoprotein upon addition of a stoichiometric amount of calcium to yield Ca(II)-alpha-LA, manifested particularly in ring current shifted aliphatic peaks and in several shifts in the aromatic region, all of which were under slow exchange conditions. The CIDNP results showed that two surface-accessible tyrosine residues, assigned as Tyr-18 and -36, became inaccessible to the solvent upon addition of 1:1 Ca(II) to apo-alpha-lactalbumin, while Tyr-103 and Trp-104 remained completely accessible in both conformers. The proton NMR spectra of apo-alpha-LA and A1(III)-alpha-LA were extremely similar, which was also consistent with intrinsic fluorescence results [Murakami, K., & Berliner, L. J. (1983) Biochemistry 22, 3370-3374]. The paramagnetic cation Mn(II) bound to the strong calcium binding site on apo-alpha-LA but also to the weak secondary Ca(II) binding site(s) on Ca(II)-alpha-LA. It was also found that Co(II) bound to some secondary sites on Ca(II)-alpha-LA that overlapped the weak calcium site. All of the lanthanide shift reagents [Pr(III), Eu(III), Tb(III), Dy(III), Tm(III), Yb(III)] bound under slow exchange conditions; their relative affinities for apo-alpha-lactalbumin from competitive binding experiments were Dy(III), Tb(III), and Pr(III) greater than Ca(II) greater than Yb(III).

Animals↗
PubMed1987

Alpha-lactalbumin binding to membranes: evidence for a partially buried protein.

The self-incorporation of apo-alpha-lactalbumin (alpha-LA) into single unilamellar vesicles (SUV) of dimyristoylphosphatidylcholine (DMPC) and dipalmitoylphosphatidylcholine was demonstrated by column chromatographic analyses on Sephadex G-200 (10 mM Tris-HCl, pH 7.4, 26-28 degrees C) and by intrinsic fluorescence emission of SUV-bound alpha-LA. It was shown that apo-alpha-LA slowly incorporated into the DMPC vesicle bilayer after equilibrating different mixtures of protein and SUV for several hours. The intrinsic fluorescence properties of the bound apo-alpha-LA were altered only slightly (lambda maxem = 333 nm vs. 337 nm in aqueous solution). The large blue shift in apo-alpha-LA fluorescence in solution induced by monovalent cations, such as Na(I), was almost completely prevented when apo-alpha-LA was membrane bound. Furthermore, the addition of calcium caused a slow conversion from apo-alpha-LA to Ca(II)-alpha-LA by a mechanism consistent with passive diffusion of Ca(II) into the bilayer interior to the (buried) calcium binding site. The release of Ca(II)-alpha-LA from the membrane is discussed with reference to alpha-LA release from the smooth endoplasmic reticulum in vivo.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1987

Clinical experience with intraoperative Doppler color flow imaging in hepatectomy.

Real-time two-dimensional Doppler echography (2-D Doppler), which permits both structural and blood flow evaluations simultaneously, was applied during hepatectomy in three cases. Intrahepatic portal flow was observed in one case both before and after Pringle's maneuver. Hemihepatic blood flow interruption, which was guided by 2-D Doppler imaging, was tried in two cases. Extrahepatic blood flow was also detected easily with 2-D Doppler techniques. This approach is useful for both anatomic and hemodynamic evaluation during hepatic surgery.

Aged↗
PubMed1987

Radiotherapy for carcinoma of the uterine cervix by remotely controlled afterloading intracavitary system with high-dose-rate.

Between January 1978 and June 1985 seventy-nine patients with carcinoma of the uterine cervix were treated by a remotely controlled afterloading system (RALS) with high-dose-rate irradiation following external beam therapy. It was given once a week with a dose per fraction of 6 Gy to point A, 3 to 6 times, using applicators equipped with 1 Ci 60Co bead in each ovoid and two 1 Ci 60Co beads in a tandem 1 cm apart. Five-year survival rates were 85, 68, and 51 percent in Stages I, II, and III, respectively. Recurrences were noted in 12 patients (20%) with a minimum follow-up of 2 years: 4 patients in the parametrium, 2 in the central area, 5 in both the parametrium and central areas, and 5 in the para-aortic lymph node. Complications were noted in 13 patients (22%): temporary rectal bleeding in 7, stenosis of the sigmoid in 2, recto-vaginal fistula in 1, ileo-sigmoidal fistula in 1, and perforation of the intestine in 2 patients. The treatment results of the high-dose-rate schedule for RALS appear to be comparable to those of conventional low-dose-rate systems reported by others. Therefore a fraction dose of 6 Gy to point A once a week by RALS should be considered to be practical, economical, and acceptable to patients.

Brachytherapy↗
PubMed1987

Visualization of distal splenorenal shunt by isotopic splenovenography.

Radioisotopic angiography of the splenic vein was performed in six patients following a distal splenorenal shunt (Warren procedure). Under echographic guidance, the spleen was punctured with a 22-gauge needle, and Tc-99m pertechnetate was injected into the splenic pulp. In five patients whose esophageal varices had remained atrophic, the splenic vein, the left renal vein, the inferior vena cava, and the heart were clearly visualized within 8 seconds. In one patient, in whom recurrence of esophageal varices had been recognized, the splenic vein was not imaged. The injected material coursed mainly upwards through collaterals.

Aged↗
PubMed1987

Hemifacial spasm due to contralateral acoustic neuroma: case report.

A patient with a large acoustic neuroma had contralateral hemifacial spasm. On CT, the brainstem was markedly displaced and distorted by the tumor. After total removal of the tumor the hemifacial spasm was temporarily worse, but disappeared 14 days after the operation.

Facial Muscles↗