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Biomedical subjects

H Fujioka

Publications and source records attributed to H Fujioka.

At least 181 records · Page 10Linked to original sources

Multi-organ erythrocyte sequestration and ligand expression in rhesus monkeys infected with Plasmodium coatneyi malaria.

The pathogenesis of human cerebral malaria is suspected to be caused by blockage of cerebral microvessels by the sequestration of parasitized human red blood cells (PRBC). Examination of infected tissues indicate PRBC sequestration in microvessels is the result of PRBC knob attachment to endothelial cell surface cytoadherence receptors such as CD36, thrombospondin (TSP), and intercellular adhesion molecule-1 (ICAM-1). In lieu of fresh human tissue, several animal models for human cerebral malaria have been developed, the Plasmodium coatneyi-infected rhesus monkey model being the most versatile. To further the understanding of noncerebral malarial complications during disease, we examined noncerebral tissues of infected rhesus monkeys. Our study demonstrated similar microvessel PRBC sequestration and the presence of cytoadherence ligands in noncerebral tissues. Immunohistochemical analysis showed CD36, TSP, and ICAM-1 cytoadherence proteins in several major organs.

Animals↗

[HLA antigens in patients with testicular germ cell tumors].

The role of HLA antigens in the etiology of testicular germ cell tumor has been suggested previously. Several attempts have been made to establish associations of HLA antigens in patients with testicular cancers, but have yielded inconsistent results. We studied the frequencies of HLA antigens by serological typing and DNA typing and examined the association between testicular germ cell tumors and HLA antigens. The serological expression of HLA-A, -B, -C, -DR and -DQ antigens was analyzed in 23 patients with germ cell cancers of the testis. The findings indicated a trend towards an increase in the antigen DQ4 (p < 0.05). The 13 patients were typed for HLA DRB1 and DQB1 allele by PCR-RFLP analysis. The findings revealed an increased frequency of DRB1 0405 (p < 0.01) and DQB1 0401 (p < 0.01).

Adult↗

[Clinical evaluation of 201TI single photon emission computed tomography in patients with large opacities due to silicosis with bronchogenic carcinoma].

201T1 single photon emission computed tomography (201T1 SPECT) was used to evaluate 18 patients with large opacities due to silicosis and 22 others with bronchogenic carcinoma. An early scan and a delayed scan were obtained and the retention index was calculated from the early ratio and the delayed ratio. In patients with silicosis, the retention index and the two ratios were significantly lower than in the patients with bronchogenic carcinoma (p < 0.01). In patients with stable shadows on chest X-ray films due to large opacities of silicosis, the delayed ratio was the same as or lower than the early ratio. However, in patients with silicosis who had high activity in large opacities, the delayed ratio was higher than the early ratio. These results suggest that 201)T1 SPECT is useful for evaluating the activity of large opacities in patients with silicosis and for differentiating large opacities caused by silicosis from those caused by bronchogenic carcinoma.

Aged↗

[Recurrence of the acute respiratory distress syndrome in a patient with liver cirrhosis and diabetes mellitus].

The acute respiratory distress syndrome developed twice within 4 months in a patient with liver cirrhosis and diabetes mellitus. The diagnosis was made from the diffuse alveolar shadows seen on a chest X-ray film and a lung injury score of 3.3. The initial episode resolved quickly with steroid pulse therapy. The second episode resolved to some extent after the same therapy, but the patient died of hepatic and renal failure followed by acute pneumonia. The causes of the first and second episodes were considered to be different and the outcome depended on liver and kidney function. We report this case because the acute respiratory distress syndrome rarely occurs within 4 months.

Acute Disease↗

Differential patterns of reaction of human natural antibodies to pig hepatocytes and vascular endothelium.

We have recently conducted a series of experiments to characterize the pattern of reaction of human natural antibodies (NA) with individual pig liver cells. Pooled normal human serum (PHS) was incubated with cultured pig hepatocytes (HEP), aortic endothelial cells (AEC), and portal endothelial cells (PEC), and the reaction of NA to different cell types was measured by antibody-mediated cytotoxic (MTT assay), antibody binding (ELISA), and flow cytometric analysis. The human NA displayed a differential pattern of binding with hepatocytes exhibiting a more limited expression of xenoantigen expression than either aortic or portal endothelial cells. These differences in reaction patterns were also noted for Western blot analysis of individual cell membrane extracts. Preincubation of the pig cells with anti-pig MHC antibodies did not inhibit the binding of human IgM natural antibodies to the pig cells. Comparison of the pattern of NA absorption following the use of bioartificial liver support in patients with acute hepatic failure demonstrated limited ability of pig hepatocytes to absorb substantial amounts of NA. These studies indicate that pig hepatocytes are less vulnerable to NA cytotoxicity than pig vascular endothelial cells and that pig vascular endothelial cells express xenoantigens that are unique and not found on hepatocytes.

Animals↗

Plasmodium gallinaceum: a refractory mechanism of ookinete killing in the mosquito, Anopheles gambiae.

We have identified a mechanism for refractoriness to a bird malaria, Plasmodium gallinaceum, in the African vector of human malaria, Anopheles gambiae. Oocysts fail to develop in the refractory mosquitoes as a result of ookinete death which occurs within 27 hr of midgut invasion. Ultrastructural studies showed that parasite death occurs while the ookinete lies free in the midgut epithelial cell cytosol, usually surrounded by an organelle-free zone that consists of finely fibrillar material. The mechanism of parasite killing does not involve a previously described refractory mechanism of parasite encapsulation. We selected genetic lines which are refractory and susceptible to midgut infection. Genetic crossing of the lines suggests that the refractory trait is inherited as a single dominant genetic locus. Other loci probably influence oocyst number in susceptible mosquitoes. Intracellular ookinete killing appears to involve a previously unrecognized host defense mechanism against malaria parasites that involves direct destruction of the invading organism.

Animals↗

Analysis of tardy ulnar nerve palsy associated with cubitus varus deformity after a supracondylar fracture of the humerus: a report of four cases.

Four cases of tardy ulnar nerve palsy associated with a cubitus varus deformity of the elbow secondary to a supracondylar fracture of the humerus are presented. All patients had surgical management of their ulnar nerve palsy. In two patients, the ulnar nerve was entrapped by scar tissue at the abnormal position and the nerve developed a sharp V-shaped kink when the elbow was flexed. In one patient, the ulnar nerve displaced anteriorly with elbow flexion and spontaneously reduced into the ulnar nerve groove with elbow extension. In one patient, the ulnar nerve remained in the ulnar nerve groove; however, it was entrapped by fibrous bands arising from the flexor carpi ulnaris. It is speculated that malunion resulting in cubitus varus deformity will alter the anatomy at the elbow and that this can have a direct effect on the position and instability of the ulnar nerve. Incongruity of the elbow joint due to cubitus varus deformity also may cause osteoarthritis changes. As a result, ulnar neuropathy may develop from irritation to the ulnar nerve from the posttraumatic osteoarthritic changes at the elbow joint.

Adolescent↗

Plasmodium falciparum protein associated with the invasion junction contains a conserved oxidoreductase domain.

The merozoite cap protein-1 (MCP-1) of Plasmodium falciparum follows the distribution of the moving junction during invasion of erythrocytes. We have cloned the gene encoding this protein from a cDNA library using a monoclonal antibody. The protein lacks a signal sequence and has no predicted transmembrane domains; none of the antisera reacts with the surfaces of intact merozoites, indicating that the cap distribution is submembranous. MCP-1 is divided into three domains. The N-terminal domain includes a 52-amino-acid region that is highly conserved in a large family of bacterial and eukaryotic proteins. Based on the known functions of two proteins of this family and the pattern of amino acid conservation, it is predicted that this domain may possess oxido-reductase activity, since the active cysteine residue of this domain is invariant in all proteins of the family. The other two domains of MCP-1 are not found in any other members of this protein family and may reflect the specific function of MCP-1 in invasion. The middle domain is negatively charged and enriched in glutamate; the C-terminal domain is positively charged and enriched in lysine. By virtue of its positive charge, the C-terminal domain resembles domains in some cytoskeleton-associated proteins and may mediate the interaction of MCP-1 with cytoskeleton in Plasmodium.

Amino Acid Sequence↗

Controlled release by Ca(2+)-sensitive recombinant human tumor necrosis factor-alpha liposomes.

Recombinant human tumor necrosis factor-alpha (rHuTNF) was entrapped in liposomes consisting of Egg phosphatidylcholine (EggPC) alone, EggPC-egg phosphatidic acid (EggPA) or EggPC-egg phosphatidylglycerol (EggPG). These liposomes, stored in vials, were stable for a month at 4 degrees C. The rHuTNF release from the liposomes were examined in rat plasma and phosphate buffered saline (PBS). rHuTNF was released from the liposomes containing EggPA in rat plasma. The release of rHuTNF was inhibited by EDTA and was induced in PBS containing CaCl2, indicating that this release is induced by Ca2+ ion in the plasma. The release of rHuTNF was promoted by an increase of the EggPA content. In conclusion, we could obtain stable liposomes in a vial and this liposome could immediately release rHuTNF in the rat plasma. Furthermore we were able to control the release rate of rHuTNF from these liposomes.

Animals↗

Purification and characterization of angiotensin II degradation factor from porcine endothelial cells.

We investigated the degradation of angiotensin II by vascular endothelial cells and smooth muscle cells in vitro. When angiotensin II was incubated with confluent culture of endothelial cells or with serum free conditioned medium of the endothelial cells, angiotensin II was destroyed rapidly. When angiotensin II was incubated with cultured vascular smooth muscle cells or their serum free conditioned medium, degradation was not observed. To identify the angiotensin II degradation factor (ADF), we have purified ADF from the conditioned medium of endothelial cells, by column chromatographies, i.e., hydroxyapatite, ion exchange and gel filtration chromatography. The partially purified ADF had apparent molecular masses of 154 kDa on gel filtration chromatography. Its pH optimum was about 7.0. ADF was inhibited by p-chloromercuribenzoic acid, iodoacetamide and high concentration of EDTA, but not by diisopropyl fluorophosphate, bestatin, amastatin or pepstatin A. Of the synthetic substrates examined, ADF degrades human angiotensin II, [Val5]-angiotensin II and [Asn1, Val5]-angiotensin II. It did not degrade angiotensin I.

Ammonium Sulfate↗

[Clinical features of acute pulmonary embolism in the elderly].

The clinical features of acute pulmonary embolism were evaluated and compared between Group A with 38 cases > 65 years old and Group B with 73 cases < 65 years old. The mortality rate was 58% (22/38) in Group A and 23% (17/73) in Group B (p < 0.01). However the size of the obstructive pulmonary vascular bed showed no significant difference in both groups. In group A dyspnea was the most common symptom in 27 of 31 (87%), in comparison with group B [45 of 66 (68%), p < 0.05]. In group B, dyspnea and other symptoms appeared abruptly in 44 of 57 (77%), compared with 19 of 36 (53%) in group A (p < 0.02). ECG abnormalities including tachycardia, right bundle branch block and clockwise rotation as well as hypoxemia were present more predominantly in group A. The presentation of pulmonary embolism is variable in the elderly, as in any age group. Many autopsy studies showed a significant rise in incidence of pulmonary embolism in higher age groups. We must keep in mind the characteristics of clinical features in pulmonary embolism in the elderly.

Acute Disease↗

A correlation between sequestered parasitized erythrocytes in subcutaneous tissue and cerebral malaria.

Sequestered parasitized erythrocytes were found in microvessels of subcutaneous tissues in a comatose patient with cerebral malaria even though the blood smears were negative after quinine treatment. This situation reflects the continued presence of sequestered parasites in the brain and suggests that negative parasitemia in peripheral blood does not necessarily mean the end point of malarial treatment has been reached. Our findings suggest that biopsy of subcutaneous tissue from severe malaria patients may be useful for determining the severity and prognosis of malaria patients.

Adult↗

[Immunological study of the postoperative adjuvant treatment with interferon gamma in patients with renal cell cancer--measurement of peripheral blood lymphocyte subsets with three color flow cytometry].

The antitumoral effects of interferon (IFN) against renal cell carcinomas (RCC) are considered to consist of a direct tumoricidal activity and an indirect action related to the host immune system. Monitoring to T lymphocytes is an immunological parameter to evaluate the antitumoral effects of IFN. To examine in detail the change of CD8 positive cells reported previously, we analyzed the change of the peripheral blood T lymphocyte subsets using three color flowcytometry during the period of IFN-gamma administration. We administered recombinant interferon gamma (rIFN-gamma) to the patients with renal cell cancer. Eighteen patients received a prophylactic injection of rIFN-gamma (300 x 10(4) units per week) after nephrectomy. Among them three patients developed distant metastases and one had local recurrence after the start of rIF-gamma therapy. We evaluated the immunological change by measurement of the peripheral blood lymphocyte subsets consisting of activated cytotoxic T lymphocytes (ACTL), activated suppressor T lymphocytes (ASTL), activated suppressor-inducer T lymphocytes (AITL), cytotoxic T lymphocytes (CTL), helper T lymphocytes (HTL), and suppressor-inducer T lymphocytes (SITL), from the start of rIFN-gamma injection. We also estimated the natural killer (NK) activity by a cytolytic test at the same points. NK activity consecutively increased throughout the period of administration of rIFN-gamma. We found significant enhancement of ACTL at the sixth month (P < 0.05), ASTL at the third month (P < 0.01) and NK activity at the second week, the first month, the third month and the sixth month (P < 0.01) after the start of rIFN-gamma injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Two cases of acute massive pulmonary embolism diagnosed by pulmonary angiography with Swan-Ganz catheter].

We report two cases of acute massive pulmonary embolism diagnosed at the bedside by pulmonary angiography with Swan-Ganz catheter. In both cases the patients (women 48 and 49 years old) went into shock after surgery. Pulmonary angiography with Swan-Ganz catheter was done at the bedside to confirm the diagnosis. In both cases this revealed filling defects. Hemodynamics improved after-thrombolytic therapy. In general, pulmonary embolism can be definitively diagnosed by lung perfusion scan or pulmonary angiography. Pulmonary angiography with a Swan-Ganz catheter is useful in hospitals without complicated instruments, but is indicated only for unmovable and unstable patients with hemodynamic problems.

Acute Disease↗