Biomedical subjects

H Hashizume

Publications and source records attributed to H Hashizume.

At least 127 records · Page 7Linked to original sources

PubMed1996

Dilazep and its derivative, K-7259, attenuate mechanical derangement induced by palmitoyl-L-carnitine in the isolated, perfused rat heart.

The effect of dilazep, a potentiator of the adenosine-mediated effects, on the palmitoyl-L-carnitine (PALCAR)-induced mechanical derangement was studied in the isolated rat heart and compared with that of K-7259, a dilazep derivative having less potentiating action on the adenosine-mediated effects. The heart was perfused aerobically by the Langendorff's technique at a constant flow and driven electrically. PALCAR (5 microM) decreased the left ventricular developed pressure and increased the left ventricular end diastolic pressure in the heart (i.e., mechanical dysfunction). These mechanical alterations induced by PALCAR were attenuated by dilazep (1 microM) and K-7259 (1 microM). In contrast, adenosine (10 or 100 microM) did not attenuate the PALCAR-induced mechanical derangement. On the other hand, neither dilazep nor K-7259 modified the mechanical function of the normal (PALCAR-untreated) heart. These results suggest that dilazep and K-7259 attenuate the PALCAR-induced mechanical derangement and that the protective action of both drugs is not due to potentiation of adenosine-mediated effects.

Adenosine↗

PubMed1995

Photodynamic DNA-breaking activity of serum from patients with various photosensitivity dermatoses.

Various drugs and chemicals break the DNA strand under ultraviolet irradiation. This study aimed to clarify the DNA-breaking activity (DBA) of serum from 39 patients with various photosensitivity disorders and that from eight normal subjects. A mixture of serum and circular plasmid DNA was exposed to longwave ultraviolet radiation, and the photoinduced cleavage of plasmid DNA was examined by electrophoretic analysis. DBA was found in serum from patients with erythropoietic protoporphyria (2 of 2), drug-induced photosensitivity (3 of 5), chronic actinic dermatitis (1 of 12) and hydroa vacciniforme (1 of 1). DBA was not found in serum from patients with porphyria cutanea tarda, collagen diseases with photosensitivity, papulovesicular light eruption or pellagra. The inhibition profile of DBA by active oxygen scavengers was different between afloqualone- and tetracycline-induced photosensitivity and chronic actinic dermatitis. The present method was useful for the detection of serum phototoxicity and the investigation of the pathomechanisms of photosensitivity.

Adult↗

PubMed1995

Intraneural ganglion of the posterior interosseous nerve with lateral elbow pain.

We report an intraneural ganglion of the posterior interosseous nerve causing lateral elbow pain. The cystic lesion was identified by magnetic resonance imaging, and surgical exploration using the microscope permitted complete extirpation of the cyst without damage to nerve tissue. The patient experienced complete relief from pain, with full preservation of function.

Adult↗

PubMed1995

Delayed posterior interosseous nerve palsy.

A rare case of delayed posterior interosseous nerve palsy that developed 39 years after an unreduced anterior dislocation of the radial head is reported. The posterior interosseous nerve was compressed and narrowed at the arcade of Frohse. Radial head resection and release of the arcade was done. The paralysis continued to recover 6 weeks after operation. The nerve, at the arcade of Frohse, was susceptible to compression by the dislocated radial head, especially in the supinated position. Repeated supination and pronation movement over time may have led to developmental changes that caused the delayed nerve palsy.

Adult↗

PubMed1995

Ewing's sarcoma of the hand: magnetic resonance images and treatment.

Two cases of Ewing's sarcoma of the hand were treated by preoperative chemotherapy and radiation therapy to decrease tumor volume. Magnetic resonance images were useful in showing the soft tissue mass and in estimating the effect of the chemotherapy. The results of surgery were satisfactory with this treatment regimen.

Adult↗

PubMed1995

Malignant hemangioendothelioma.

BACKGROUND: The administration of interleukin-2 (IL-2) has recently been reported to be favorable for treating malignant hemangioendothelioma (MHE). METHODS: Two patients with MHE responded well to intralesional injections of recombinant IL-2 (rIL-2) without major side effects. The purpose of this study was to characterize cells infiltrating the regressing tumor following rIL-2 treatment. Immunohistochemical studies were performed on biopsy specimens taken from rIL-2-injected lesional skin. RESULTS: It was shown that CD8+ lymphocytes and CD56+ natural killer (NK) cells infiltrated at the rIL-2-injection sites, suggesting that these cells contributed to the tumor regression. In addition, MHE cells bore intercellular adhesion molecule-1 (ICAM-1) whose expression was augmented by rIL-2 injections. CONCLUSIONS: These findings suggested, that rIL-2 not only induces lymphokine-activated killer (LAK) cells and NK cells, but also facilitates these cytotoxic cells to adhere to MHE cells by enhancing ICAM-1 expression of tumor cells.

Aged↗

PubMed1995

A study on dilazep: I. Mechanism of anti-ischemic action of dilazep is not coronary vasodilation but decreased cardiac mechanical function in the isolated, working rat heart.

In the isolated, perfused working rat heart, ischemia (15 min) decreased the mechanical function and the tissue levels of adenosine triphosphate and creatine phosphate and increased the levels of lactate and free fatty acids. Reperfusion (20 min) did not restore the mechanical function, but restored incompletely the levels of metabolites, with the exception of free fatty acids, which increased further during reperfusion. Dilazep was given 5 min before starting ischemia until the end of ischemia. Dilazep at 5 or 10 microM decreased the cardiac mechanical function, but did not affect coronary flow in the pre-ischemic heart. Dilazep at 5 or 10 microM accelerated the recovery of mechanical function and coronary flow during reperfusion, and it attenuated metabolic changes induced by ischemia and reperfusion. Dilazep at 1 microM neither decreased the pre-ischemic mechanical function nor restored the mechanical function during reperfusion, although it attenuated the accumulation of free fatty acids during reperfusion. These results suggest that dilazep attenuates both ischemia- and reperfusion-induced myocardial damage and that the anti-ischemic action of dilazep is not due to coronary vasodilation but probably due to an energy-sparing effect and other effects that remain to be studied.

Animals↗

PubMed1995

A study on dilazep: II. Dilazep attenuates lysophosphatidylcholine-induced mechanical and metabolic derangements in the isolated, working rat heart.

The effects of dilazep, d-propranolol and lidocaine on the mechanical and metabolic changes induced by lysophosphatidylcholine (LPC) were studied in isolated, perfused working rat heart. After a stabilization period, the heart was perfused for 5 min with LPC (10 microM) alone, LPC plus dilazep (5, 10 or 20 microM), LPC plus d-propranolol (30 or 50 microM) or LPC plus lidocaine (30 or 100 microM) and then perfused with normal Krebs-Henseleit bicarbonate (KHB) buffer for a further 20 min. Perfusion with LPC for 5 min followed by KHB for 20 min irreversibly decreased cardiac mechanical function, decreased the tissue levels of adenosine triphosphate and creatine phosphate significantly, and increased the tissue levels of lactate and free fatty acids including arachidonic acid. Dilazep or d-propranolol significantly attenuated the mechanical and metabolic changes induced by LPC, but lidocaine did not. These results indicate that the exogenous LPC causes ischemia-like changes, suggesting that LPC is one of the important factors in producing ischemia-reperfusion derangements in terms of mechanical and metabolic functions, and that both dilazep and d-propranolol can prevent the LPC-induced myocardial damage.

Animals↗

PubMed1995

A histological study of the cardiac muscle of the human superior and inferior venae cavae.

Human superior and inferior venae cavae at the orifices to hearts obtained from two cadavers were histologically examined with regard to the distribution of cardiac muscle fibers in their walls. The superior vena cava contained cardiac muscle fibers together with smooth muscle fibers. The cardiac muscle fibers were distributed uninterruptedly from the atrium to the root of the azygos vein, covering a length of 45 mm. Cardiac myocytes were present outside the smooth muscle and coursed in bundles longitudinally, obliquely, or circularly. Cardiac myocytes occupied one to two thirds of the wall thickness, but decreased in amount toward the periphery. The inferior vena cava also contained both cardiac and smooth muscle fibers. The cardiac muscle fibers extended continuously, covering a distance of 18 mm from the atrium to a level just under the diaphragm. Their fibers were bundled, running circularly or obliquely, and being more abundant in the anterior wall than in the posterior. From these findings, the venae cavae close to the atrium are histologically regarded as an extension of the atrium. The venae cavae close to the atrium probably contract together with the atrium and work as a functional valve that contributes to the pumping mechanism of the heart.

Humans↗

PubMed1995

Rotationplasty for patients with osteosarcoma around the knee joint.

The results of rotationplasty for patients with osteosarcoma around the knee joint are presented. After an average observation period of 13.3 months, there has been no local recurrence or metastasis. The ankle joints (the new knee joints) of the patients were able to support their body weight with an average range of motion of 75 degrees. All patients could walk well without crutches and without risk of the giving way phenomenon. The average rate of the functional evaluation according to the re-modified system by Enneking was 84.5% (range, 80.0-86.7%). No patient had psychological trouble in accepting the shortened and rotated extremity. The results show that rotationplasty is a useful reconstructive method for the treatment of osteosarcoma around the knee joint.

Adolescent↗

PubMed1995

Finite element analysis of pathogenesis of osteoarthritis in the first carpometacarpal joint.

Stress distribution in the first carpometacarpal joint was analyzed in 49 cadaveric hands using the finite element method to clarify the pathogenesis of osteoarthritis in the joint. The results of the finite element method analysis were compared with those of the contact pressure distribution in the first carpometacarpal joint of cadaveric specimens using pressure-sensitive film, and with the simple roentgenographical and microradiographical manifestations of spur formation, and with histological findings of osteoarthritis to verify the accuracy of the models of computer simulation models. The comparison of these results showed that osteoarthritic changes of the first carpometacarpal joint were found in areas where stress was concentrated during movement of the joint. The saddle shape of this joint is essentially well-designed for the dispersion of normal stress, however minimal displacement due to instability could easily induce osteoarthritis. Furthermore the shallow trapezial configuration may contribute to the high incidence of osteoarthritis changes. The finite element method helped clarify the relationship between stress patterns and osteoarthritis response.

Computer Simulation↗

PubMed1994

Effects of antiischemic drugs on veratridine-induced hypercontracture in rat cardiac myocytes.

The effects of different groups of substances (beta-adrenoceptor antagonists, Ca2+ channel blockers and vasodilators) which are known to have antiischemic properties were studied on veratridine-induced hypercontracture. Veratridine increases Na+ influx by slowing the inactivation process of the Na+ channel, thereby inducing a continuously increased Na+ entry in depolarized cells. Veratridine (6.3 x 10(-6) M) produced a change in cell shape from rod-shape to round, resulting from hypercontracture of cells. Before treatment with veratridine the proportion of rod-shaped cells was 70% and fell to 0% 5 min after the treatment with veratridine. dl-Propranolol, d-propranolol, l-penbutolol, d-penbutolol, nisoldipine, and dilazep all inhibited veratridine-induced hypercontracture dose dependently. In contrast, acebutolol, atenolol, timolol, nifedipine, diltiazem, and nitroglycerin did not inhibit the rounding of cells. Concomitantly with the rounding of cells, the [Ca2+]i was increased by veratridine. dl-Propranolol, d-propranolol and dilazep prevented the increase of [Ca2+]i induced by veratridine, whereas timolol and nitroglycerin did not. These results show that dl-propranolol, d-propranolol, l-penbutolol, d-penbutolol, nisoldipine, and dilazep possess Na+ channel blocking actions on the veratridine-modified Na+ channel, thereby preventing excessive Na+ influx and secondary Ca2+ overload.

Adrenergic beta-Antagonists↗

PubMed1994

Cystic radio-lucency of carpal bones in haemodialysis patients. An early indicator of the onset of carpal tunnel syndrome.

Patients receiving haemodialysis for more than 10 years were selected for this study in order to clarify an apparent sequential association of cystic lesions of carpal bones and carpal tunnel syndrome. X-rays and computed tomographs of 138 hands of 69 patients revealed cystic radiolucency of carpal bones in 35% of the hands. Radiographs were classified into three groups: Group A--cyst growing, Group B--cyst not growing, and Group C--cyst absent. The prevalence of carpal tunnel syndrome was 100% (27/27) in Group A, 5.6% (1/18) in Group B, and 6.5% (6/93) in Group C. Growth of the cyst precedes the development of carpal tunnel syndrome by about 2 or 3 years. Growth of the bone cyst indicates that inflammation had already extended to the tenosynovium and median nerve. Cystic radio-lucency of the carpal bones appears to be a useful indicator of the onset of carpal tunnel syndrome.

Adult↗

PubMed1994

Cubital tunnel syndrome in a patient in long-term haemodialysis.

The onset mechanism of cubital tunnel syndrome and carpal tunnel syndrome may be similar in haemodialysis patients. Carpal tunnel syndrome is well recognized as a consequence of dialysis-associated amyloidosis. This case report documents the development of cubital tunnel syndrome in a patient on haemodialysis treatment for 10 years. Proliferating granulation tissue at the elbow had entrapped and displaced the ulnar nerve. This was corrected surgically, and the patient experienced immediate relief of the numbness and the "tingling", but the muscular atrophy had not improved after 8 months.

Humans↗

PubMed1994

Malunited Colles' fracture. Analysis of stress distribution.

To try to explain disability in the wrist after malunited Colles' fractures, an experiment was designed to evaluate pressure distribution through the wrist joint with varying degrees of angulation of the distal radius. The results of computer simulation analysis of stress concentration using finite element methods were compared with those of pressure distribution studies on the radial articular surface of cadaveric radii in various positions using pressure-sensitive film. Stress existed in volar regions of the radio-lunate joint under normal pressure in the neutral position, but shifted to dorsal regions of the joint, and was concentrated when dorsal angulation reached 30 degrees. We believe that concentrated loads result in pain and may lead to early degenerative joint disease. Early additional reduction of a displaced fragment or a post-fusion osteotomy should be considered when dorsal angulation exceeds 30 degrees in malunited distal radial fractures to decrease abnormal loading across the wrist joint.

Adolescent↗

PubMed1994

Increased number of dendritic epidermal T cells associated with induced anagen phase of hair cycles.

With the use of immunofluorescent staining we investigated the number and the morphologic and phenotypic changes of murine dendritic epidermal T cells (DETC) at various phases of the hair cycle that were synchronized by depilation. The epidermis on day 1 after depilation contained a small number of DETC, round DETC populated at perifollicular space on day 7, and then a large number of DETC with conspicuous dendrites were found mainly at interfollicular space on day 10. This suggests that the in situ proliferation of DETC may be correlated at least partly to the hair cycle, and that hair follicles, which are major skin appendages, may be involved in cutaneous immunity.

Aging↗

PubMed1994

Lymphomatoid papulosis associated with acquired ichthyosis.

We describe a 64-year-old man with lymphomatoid papulosis associated with acquired ichthyosis. The papulonodular lesions were composed of large atypical lymphocytes positive for CD3, CD4, and Ki-1. The ichthyosiform eruption also occurred on the extremities and had the histologic features of ichthyosis vulgaris. Although monoclonality of infiltrating cells could not be demonstrated, acquired ichthyosis appears to be induced in patients with lymphomatoid papulosis by the same pathomechanism underlying other lymphoproliferative diseases.

CD4-Positive T-Lymphocytes↗

PubMed1994

Accessory cell ability of Langerhans cells for superantigen is resistant to ultraviolet-B light.

We examined the effects of ultraviolet-B (UVB) irradiation on the accessory cell ability of Langerhans cells (LC) to induce a T-cell response to a superantigen, staphylococcal enterotoxin B (SEB). The ability of LC-enriched epidermal cells (LC-EC) to evoke a T-cell response to SEB was retained at the doses of UVB (up to 40 mJ/cm2) that profoundly affected the antigen-presenting function of LC-EC for a hapten, trinitrophenyl (TNP), and a protein antigen, conalbumin. Thus, the LC accessory function for superantigens is more resistant to UVB irradiation than that for ordinary antigens. This UVB resistance is presumably due to no requirement of antigen processing for superantigens as chemically fixed or chloroquine-treated LC-EC still retained their ability to induce T-cell responses to SEB. Higher doses of UVB (more than 60 mJ/cm2) reduced the accessory cell ability of LC-EC for SEB up to 50% of control. The addition of monoclonal antibodies against adhesion molecules between LC and T cells to the culture resulted in a substantial suppression of the T-cell response to SEB induced by nonirradiated LC-EC, while the UVB-irradiated LC-EC-induced T-cell response was not significantly blocked with these monoclonal antibodies. This suggested that the reduction of LC ability for superantigen by high doses of UVB is at least partly due to the impairment of adhesion molecules on LC by UVB irradiation.

Animals↗