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Biomedical subjects

K Hara

Publications and source records attributed to K Hara.

At least 541 records · Page 30Linked to original sources
PubMed1994

[A drug delivery system and biological response modifiers for the treatment of mycobacterial infection].

A drug delivery system (DDS) for the treatment of infectious disease has recently been developed. Since liposomal antimicrobial agents are effective on cytozoic bacteria, we applied liposomal streptomycin and amikacin for the treatment of systemic mycobacterial tuberculosis in mice. Liposomal aminoglycosides showed excellent efficacy compared to free aminoglycosides or empty liposome. This therapeutic strategy should be developed for clinical application. Although the human defense mechanism against microbial infection is very complicated, biological response modifiers (BRM) such as vaccination or cytokine therapy have been investigated. One of the most useful and protective vaccines for prevention of tuberculosis is the Mycobacterium vaccae vaccine, developed by Stanford et al. As for the cytokines, interleukin-2, granulocyte macrophage-colony stimulating factor, and tumor necrosis factor have very strong antimycobacterial activity. Interferon alone, however, has weak efficacy, and should be combined with other effective cytokines. These BRM constitute an excellent strategy for antimycobacterial chemotherapy.

Amikacin↗
PubMed1994

[Relationship between thermal threshold and population of peripheral nerve fibers].

The relationship skin thermal threshold (TT) and density of both myelinated and unmyelinated fibers were investigated in 12 patients with various peripheral nerve diseases including Crow-Fukase syndrome, carcinomatous neuropathy and Charcot-Marie-Tooth disease. The TT was measured at a site above the medial tibial condyle using a thermal threshold tester. The TT was defined as the threshold at which a slight rise or fall in temperature could be detected. The size of the skin stimulation area was 13.5 cm2, the temperature change rate was 1 degrees C/sec, and the basal temperature was set at 34 degrees C. A sural nerve biopsy was performed and an image processor (IBAS) was used to measure the nerve fiber density. The TT in the patients with peripheral nerve disease was found to be elevated when compared with that of the 74 healthy controls (mean age of 38.1 +/- 13.3 years). Elevation of the TT has an intimate relation to damage of the small myelinated nerve fibers. In conclusion, unmyelinated fibers may play a relatively minor role in conveying thermal sensation.

Adult↗
PubMed1994

[Magnetic resonance imaging of spinal cord lesions in 22 multiple sclerosis patients].

We reviewed MRI findings in 22 patients (37 cases) with clinically diagnosed multiple sclerosis (MS) with spinal cord lesions. The spinal cord lesions were detected in 17 (46%) of these 37 cases on MRI. The cervical cord lesions were more detectable than other spinal cord lesions. At the thoracic level, the upper lesions were more detectable than the lower ones. In this study, no correlation was found between the disease duration, the rate of functional disturbance and the detectable rate of spinal cord lesions. The characteristic findings of the lesions were swelling and the enhancement effect of Gd-DTPA in the patient group with a disease duration of less than three years, and atrophic change in the patient group with a disease duration of greater than seven years. The period of the enhancement effect of Gd-DTPA varied in each case, and it may reflect the clinical course. Syrinx-like lesions were found in four cases. In one of them, atrophic change was found in the same region six months after the follow up study. Although the precise reason for the syrinx-like lesion was unclear, a relationship between syrinx-like lesion and atrophy of the spinal cord was suggested. The MRI findings of the spinal cord lesions in MS varied in each case and in each stage of the disease.

Adolescent↗
PubMed1993

[Basic study of bone mineral density in os calcis by single energy X-ray absorptiometry].

We studied bone mineral density (BMD) in the os calcis by means of single energy X-ray absorptiometry (SXA), and BMD in the third lumbar spine by means of dual energy X-ray absorptiometry (DXA), results were as follows. (1) The doses absorbed in SXA at the exposure site and the opposite site were measured by thermoluminescent dosimetry. The dose absorbed in SXA may be lower than that in DXA. (2) The BMD of the os calcis was measured in 30 female volunteers by SXA and that of the third lumbar spine by DXA, and age, weight, height, and consequences of physical exertion were investigated. BMD as determined by SXA was significantly correlated with that determined by DXA (r = 0.65). BMD as determined by SXA and DXA tended to decrease with age, to increase with height and weight, and to be significantly higher in those who made some physical exertion. In conclusion, SXA may be a useful method for the measurement of BMD.

Absorptiometry, Photon↗
PubMed1993

The crystal and molecular structure of beta-D-fructofuranosyl alpha-D-xylopyranoside hemihydrate.

The crystal and molecular structure of beta-D-fructofuranosyl alpha-D-xylopyranoside (xylosucrose) hemihydrate, C11H20O10.0.5H2O, is orthorhombic, P2(1)2(1)2, with a = 20.919(5), b = 18.727(2), c = 7.071(1) A, V = 2770.1(2) A3, Z = 8, and Dx = 1.541 g.cm-3. The structure was solved by direct methods and refined to R = 0.040 for 2564 observed reflections. Two independent xylosucrose molecules exist in the unit cell, and their conformations about the 1-->2' glycosidic bond are similar to sucrose. The orientations of the primary hydroxyl groups in the two molecules differ. An O-1'...O-2 intramolecular hydrogen bond was observed in the one molecule, while an O-6'...O-5 intramolecular hydrogen bond was observed in the other involving disorder of O-6'.

Carbohydrate Sequence↗
PubMed1993

Preparation, isolation, and characterization of novel heterogeneous branched cyclomalto-oligosaccharides having beta-D-galactosyl residue(s) on the side chain.

Transgalactosylated products of branched cyclodextrins (glucosyl-alpha CD, -beta CD, -gamma CD, and maltosyl-alpha CD, -beta CD, -gamma CD) were synthesized by beta-D-galactosidases from Bacillus circulans and Penicillium multicolor using lactose as a donor substrate and branched CDs as acceptors. Eighteen beta-D-galactosylated branched CDs were isolated and purified by HPLC. Their structures were elucidated by FABMS and 13C NMR spectroscopies, and methylation analysis. The chromatographic behavior of these novel heterogeneous branched CDs on three HPLC columns of different separation modes was compared.

Bacillus↗
PubMed1993

Differential regional hemodynamic changes produced by L-glutamate stimulation of the locus coeruleus.

The locus coeruleus (LC) exerts an inhibitory influence on the cardiovascular system. Microinjection of the excitatory amino acid, L-glutamate, into the LC elicits a decrease in arterial pressure as a result of a decrease in total peripheral resistance (TPR). The aim of the present study was to examine the role of the LC in the regulation of the regional hemodynamics. Employing anesthetized rats, the blood flow to the renal, mesenteric and hind-limb vascular beds was measured with an electromagnetic flowmeter. The changes in regional blood flow and vascular resistance evoked by chemical stimulation of the LC were examined separately in each region. During the depressor response elicited by LC stimulation, the hind-limb and renal vascular resistance was significantly decreased, while the mesenteric resistance was unchanged. The vasodilatation appeared to be more prominent in the hind-limb muscle than in the systemic circulation. Renal nerve denervation attenuated the decrease in renal vascular resistance elicited by LC stimulation. However, a small part of this response still remained in the denervated kidney. The present results suggest therefore that: (1) LC neurons exert differential hemodynamic effects on the hind-limb muscle, renal and mesenteric vascular beds; (2) the largest contribution to the decrease in TPR is related to vasodilatation in the hind-limb muscles; and (3) the renal vasodilation elicited by LC stimulation is not mediated solely by the renal innervation.

Animals↗
PubMed1993

Transfusion-associated graft-versus-host disease in an immunocompetent patient following accidental injury.

We report a case of transfusion-associated graft-vs.-host disease (TA-GVHD) in a previously healthy, 58 year old Japanese man following an accidental injury. Despite intensive treatment, the patient died 22 days after the transfusion. Although many cases of fatal TA-GVHD have been reported in immunocompetent patients, only two are known to have developed this disorder unrelated to a surgical procedure. This is the first such case to be confirmed by HLA typing. Our report suggests that TA-GVHD can occur even in a healthy, immunocompetent recipient. Thus, it seems necessary to establish guidelines for the irradiation of cellular blood products before transfusion.

Accidental Falls↗
PubMed1993

Transluminal extraction atherectomy and adjunctive balloon angioplasty for restenosis after Palmaz-Schatz coronary stent implantation.

Two patients who developed restenosis after implantation of Palmaz-Schatz coronary stents were successfully treated by transluminal extraction atherectomy and there has been no recurrence on follow-up angiograms. The optimum strategy for managing restenosis after coronary stenting remains unclear, but transluminal extraction atherectomy appears to be a safe and effective option.

Angioplasty, Balloon, Coronary↗