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Biomedical subjects

H Shiga

Publications and source records attributed to H Shiga.

At least 37 records · Page 2Linked to original sources

Cervical curvature in acute whiplash injuries: prospective comparative study with asymptomatic subjects.

The cervical curvature of 488 patients with acute whiplash injury was prospectively studied by comparison with 495 asymptomatic healthy volunteers. Plain radiography of the cervical spine in the neutral position was evaluated qualitatively. No significant difference was noted in frequencies of non-lordotic cervical curvature and local angular kyphosis between acute whiplash injury patients and asymptomatic subjects. No significant association was apparent between clinical symptoms and cervical curvature. These results suggest that non-lordotic cervical curvature and angular kyphosis in acute whiplash injury patients constitute normal variants rather than pathological findings.

Acute Disease↗

Cellular injury score for multiple organ failure severity scoring system.

BACKGROUND: Cellular Injury Score (CIS) is an index of cellular injury, being calculated from three parameters of intracellular metabolism: arterial ketone body ratio, osmolality gap, and blood lactate. METHODS: The usefulness of CIS as a severity scoring system for patients with multiple organ failure was prospectively evaluated in 157 consecutive patients with MOF (58 survivors, 99 nonsurvivors). RESULTS: CISs in nonsurvivors were significantly higher compared with those in survivors throughout the clinical courses. CIS was significantly correlated with the number of failing organs and mortality rate. The optimal cutoff point of CIS from receiver operating characteristics curve analysis was 4 for the maximal value during the clinical course. The changes in CIS well reflected the severity of injury in survivors and nonsurvivors who died within 2 weeks. CONCLUSION: CIS could be a useful index for mortality risk prediction and is potentially applicable as a severity scoring system for individual patients with MOF.

3-Hydroxybutyric Acid↗

Orbital high resolution magnetic resonance imaging with fast spin echo in the acute stage of Leber's hereditary optic neuropathy.

Some evidence suggests that the primary locus of the lesion in Leber's hereditary optic neuropathy (LHON) may be intraocular rather than retrobulbar. To clarify this issue, the condition of the retrobulbar portion of the optic nerve was evaluated in patients with the acute stage of LHON. High resolution MRI with fast spin echo sequences of the optic nerve complex in the orbit was carried out. Five patients with acute stage LHON were compared with seven patients with acute stage optic neuritis. On T2 weighted fast spin echo MRI, signal changes did not appear in the retrobulbar optic nerve complex in acute stage LHON. By comparison, patients with optic neuritis showed pronounced high signals in the optic nerve. Subsequent orbital MRI in the atrophic stages of the same patients with LHON showed an increase in signal intensity in the optic nerve toward the orbital apex in both eyes. The present results support the hypothesis that a primary lesion in LHON may be intraocular.

Acute Disease↗

MRI of cervical intervertebral discs in asymptomatic subjects.

We studied degenerative changes in the cervical intervertebral discs of 497 asymptomatic subjects by MRI and evaluated disc degeneration by loss of signal intensity, posterior and anterior disc protrusion, narrowing of the disc space and foraminal stenosis. In each subject, five disc levels from C2-C3 to C6-C7 were evaluated. The frequency of all degenerative findings increased linearly with age. Disc degeneration was the most common observation, being present in 17% of discs of men and 12% of those of women in their twenties, and 86% and 89% of discs of both men and women over 60 years of age. We found significant differences in frequency between genders for posterior disc protrusion and foraminal stenosis. The former, with demonstrable compression of the spinal cord, was observed in 7.6% of subjects, mostly over 50 years of age. Our results should be taken into account when interpreting the MRI findings in patients with symptomatic disorders of the cervical spine.

Adolescent↗

[Silicon of the medium in the postoperative maxillary cyst].

As part of a study on chronic inflammatory disease of the mucous membrane, silicon of the medium in postoperative maxillary cysts and in other cysts was measured, and following results were obtained. Silicon concentrations of the medium in the postoperative maxillary cysts and in the postoperative ethmoidal cysts were 34.5 ppm and 42.9 ppm (geometrical mean) respectively, and they were higher than in other primary cysts such as frontal cyst, nasal vestibular cyst, and dental cyst. The silicon content of the medium in the postoperative maxillary cyst varied with the water content of the medium; the lower the water content the higher was the silicon content and the relationship was expressed by the following equation. log S = 7.43 + 7.14 log d-6.14 log w, where S = Si (mcg), d = dry weight (g.) and w = wet weight (g.). The high concentration of silicon in the postoperative cyst was considered to be due to the large amount of silicon transudate from the surrounding fibrous tissue through a highly damaged or missing epithelial wall of the cyst.

Cysts↗

[Critical care for organ failure].

We retrospectively studied the critical care regimen for multiple organ failure (MOF) in 141 surgical MOF patients treated in the intensive care unit of Chiba University Hospital between January 1988 and April 1998. Patients with gut failure received parenteral instead of enteral nutrition for various reasons such as concomitant ileus. Of the patients with respiratory failure. 138 were placed on a ventilator and 6 received percutaneous cardiopulmonary support. Continuous hemodiafiltration (CHDF) was performed in 98 patients with renal failure. Plasma exchange was carried out in 13 patients with liver failure. Of these patients, 62 (44%) survived. Colloid osmotic pressure was used as an indicator for fluid therapy. For prophylaxis against bacterial translocation, we performed selective digestive decontamination. Recently blood purification methods, particularly CHDF, have become common in the critical care setting. CHDF is efficacious not only as continuous renal replacement therapy but also as a humoral mediator modulator and is currently the first-choice method for blood purification in critical care. In conclusion, there have been many advances in the critical care of patients with organ failure. Multidisciplinary treatment, including artificial support for failing organs, is necessary for the survival of these patients.

Cardiopulmonary Bypass↗

Evidence of presentation of multiple HIV-1 cytotoxic T lymphocyte epitopes by HLA-B*3501 molecules that are associated with the accelerated progression of AIDS.

We recently showed HLA-B35-restricted CTL activity for 10 HIV-1 epitopes in PBL from two HIV-1-infected individuals. In the present study, we established CTL clones specific for nine of these HIV-1 epitopes to confirm these HLA-B35-restricted epitopes. The specific CTL clones effectively killed the HLA-B*3501-positive target cells infected with the HIV-1 vaccinia recombinant virus. These results confirmed that nine HIV-1 CTL epitopes are presented by HLA-B*3501 molecules. The CTL activity specific for four Pol and two Nef epitopes was induced in the peptide-stimulated PBL from three or more of seven HIV-1-infected individuals, indicating that these six are common epitopes. Eight were considered strong epitopes because the specific CTL activity was detected in the cultured PBL that was once stimulated with peptides. Thus, the present study excluded the possibility that the disability of the presentation of HIV-1 epitopes by HLA-B35 molecules is associated with the accelerated progression of AIDS in HLA-B35-positive individuals. Analysis of mutated epitopes found in an HIV-1 type B strain using the CTL clones revealed that most mutated epitopes partially or markedly affect the recognition of CTL clones. Of 19 mutations that affected recognition of the CTL clones, 7 reduced peptide-HLA-B*3501 binding, while 12 affected TCR recognition. These results indicate that natural mutations of HLA-B35-restricted HIV-1 CTL epitopes affect the recognition of CTL by mechanisms that reduce both peptide binding and TCR recognition.

Acquired Immunodeficiency Syndrome↗

A case of spontaneous femoral neck fracture associated with multicentric reticulohistiocytosis: oversecretion of interleukin-1beta, interleukin-6, and tumor necrosis factor alpha by affected synovial cells.

We describe a case of left femoral neck fracture associated with multicentric reticulohistiocytosis (MR). Biopsy specimens from a skin nodule and from synovial tissue showed histiocytic multinucleated giant cells (MR cells) that are characteristic of MR. A surgical specimen from the resected femoral head revealed that multinucleated giant cells and mononuclear cells invaded the marginal subchondral bone, without evident pannus. These cells also infiltrated into the fracture site, with bone resorption by activated osteoclasts. Immunohistochemical studies of synovium from the left hip joint showed positive staining for interleukin-1beta (IL-1beta), IL-6, and tumor necrosis factor alpha, and abundant cytokine production by cultured synovial cells was demonstrated. These findings suggest that the subchondral invasion and intramedullary infiltration by MR cells caused articular destruction and/or fracture as a result of oversecretion of the cytokines.

Aged↗

Recovery of full flexion after total knee replacement in rheumatoid arthritis--a follow-up study.

Twenty-three of 327 patients with rheumatoid arthritis (38 out of 509 knees) had primary Yoshino-Shoji total knee replacements between 1984 und 1990 and were able to squat fully in the Japanese style after the procedure. Seven had died of conditions unrelated to their operations. Of the remaining 16, 5 were able to squat fully at follow-up; 2 were unable to do so, but had full passive flexion; 9 were unable to squat and did not have full flexion. The cumulative survival rates of patients able to squat were 82.2%, 65.7% and 47% at 2, 5 and 8 years after operation. At follow-up, 3 were able to walk out of doors for less than 30 min, 6 for 30 min or more and in 7 walking was unlimited. These results suggest that daily exercises are important in maintaining full flexion. The absence of complications may be due low body weight and limited activity due to the disease. patients with rheumatoid arthritis and low body weight can be encouraged to regain full flexion after total knee replacement if they wish to do so.

Activities of Daily Living↗

Prediction of consistency of meningiomas with preoperative magnetic resonance imaging.

BACKGROUND: The consistency of a meningioma is one of the important factors in determining the surgical outcome. If the surgeon is aware of the consistency of a meningioma preoperatively, the surgical plans will be influenced. A few papers have described the correlation between consistency of meningiomas and their magnetic resonance imaging (MRI) findings. However, prediction of consistency with MRI is still difficult. We have tried to predict the consistency of meningiomas with MRI findings more precisely. METHODS AND RESULTS: Fifty patients diagnosed as having intracranial meningiomas were studied with 1.5 Tesla MRI. We compared the MRI findings with tumor consistency. The intensities of the tumors were categorized into three grades (low, iso, and high) compared to that of the gray matter. T1-weighted images had no specifics, but T2-weighted images and proton density images were useful for the prediction of tumor consistency. Hyperintensity on protein density (PD) and T2-weighted images was a sign of a soft tumor. CONCLUSION: We presume that T2 and PD are useful for predicting consistency of meningiomas, and their water content is one of the main factors in their consistency. Histology may be one of the factors helpful in defining the consistency of a tumor. In this series, we found no relationship between histology and MRI findings, nor between histology and consistency. If the meningioma is believed to be hard, preoperative endovascular embolization is beneficial, which will induce necrosis of the meningioma and make it soft enough to be removed more easily and safety.

Adult↗

Patient with primary tonsillar and gastric syphilis.

A male patient with syphilitic lesions in the tonsil and stomach is presented. The patient was infected while practising oral sex with heterosexual friends. He complained of nausea and snoring; his left tonsil was enlarged. Spirochetes were detected in a smear preparation from the left tonsil. As a gastric lesion, initially believed to be cancer, appeared to result from spirochete ingestion, the case is considered to represent primary syphilis. After antibiotic therapy with ampicillin, the left tonsil returned to normal size and gastric changes were no longer evident endoscopically. Gastroscopy should be considered if syphilis of the tonsil is observed, particularly when gastrointestinal symptoms are present. Both the oral and the gastric lesion can be mistaken for malignant neoplasm.

Adult↗

Efficacy and limitation of apheresis therapy in critical care.

Apheresis therapy such as plasma exchange and plasma adsorption has become therapeutic tools in critical care. The indications for apheresis therapy in ICU patients include fulminant hepatic failure, thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS), autoimmune disease, and sepsis. During the past 11 years, 150 patients with various kinds of critical illnesses were treated with apheresis therapy in our ICU, and the overall survival rate was 50%. Apheresis therapy is especially useful in the treatment of a patient with fulminant hepatic failure because liver transplantation is seldom performed in Japan; therefore, the patient should be treated with artificial liver support. When plasma exchange is performed on the critically ill, continuous hemodiafiltration should be performed simultaneously to overcome the adverse effects of plasma exchange such as hypernatremia, metabolic alkalosis, and abrupt changes in colloid osmotic pressure and to enhance the removal rate of the causative middle molecular weight substances of hepatic failure or hepatic coma.

Autoimmune Diseases↗

Intracranial vascular stenosis and occlusion: MR angiographic findings.

PURPOSE: To investigate whether obtaining axial source images from three-dimensional Fourier transform (3DFT) time-of-flight MR angiography improves the detection of intracranial vascular stenosis and occlusion if added to maximum-intensity projection (MIP) images. METHODS: The angiograms of 103 patients who had MR angiography for evaluation of possible intracranial vascular disease were reviewed retrospectively in a quantitative and nonquantitative fashion. Diameters of vessels on MR angiograms were measured quantitatively by two reviewers using a magnifying loupe and compared with the results from conventional angiograms. Degrees of stenoocclusive disease were categorized into five classes; an artery with stenosis of 50% or greater was considered to be diseased. Another five observers also reviewed the MIP images with and without source images in a blinded fashion by means of nonquantitative visual inspection. RESULTS: In all, 23 stenoocclusive lesions of 50% or greater were available for review. In the quantitative analysis, with MIP images alone, 14 (78%) of 18 moderate and severe stenoses and four (80%) of five occlusions were identified correctly. The addition of the source images increased the sensitivity to 100% for moderate and severe stenoses and to 100% for occluded vessels. In the visual inspection study, however, no statistically significant differences were found between interpretations of MIP images alone and those of MIP images in combination with source images. CONCLUSION: In the quantitative study, interpretation of source images rather than MIP images reduced the tendency to overestimate stenosis seen with MR angiography and improved the sensitivity for detecting stenosis of 50% or greater. There was a discrepancy between the quantitative study and visual inspection. Experienced observers had a tendency to underestimate the degree of stenosis.

Adult↗

High-resolution magnetic resonance imaging of the intraorbital optic nerve and subarachnoid space in patients with papilledema and optic atrophy.

OBJECTIVE: To evaluate the orbital portion of the optic nerve and the subarachnoid space using fast spin-echo magnetic resonance imaging in normal subjects and in patients with papilledema or optic atrophy. DESIGN: Measurements of the optic nerve complex on coronal images were made using high-resolution magnetic resonance imaging with fast spin-echo sequences. PATIENTS: Twenty-one patients, including 5 patients with papilledema due to congenital hydrocephalus, intracranial tumors, or meningitis, as well as 16 patients with optic atrophy, were studied. Sixteen healthy volunteers served as controls. MAIN OUTCOME MEASURES: The longitudinal diameter of the optic nerve, the longitudinal outer diameter of the subarachnoid space, the diameter ratio, and the area of the subarachnoid space were determined. RESULTS: In normal subjects, the ring-shaped area of high signal intensity that represented the subarachnoid space was widest behind the globe, then narrowed toward the orbital apex. In patients with papilledema, the area of the subarachnoid space was markedly dilated, the optic nerve was compressed, and the nerve sheath was widened, resulting in a small diameter ratio compared with that of controls. Patients with pallor of the temporal aspect of the optic disc appeared to exhibit dilation of the subarachnoid space; the size of the optic nerve was decreased more than that of the nerve sheath, resulting in a small diameter ratio compared with controls. Patients with complete pallor of the disc, however, exhibited hyperintense optic nerve complexes without a ring-shaped appearance toward the orbital apex. CONCLUSION: Fast spin-echo magnetic resonance imaging appears useful for objectively evaluating the optic nerve and surrounding subarachnoid space in patients with papilledema and optic atrophy.

Adolescent↗

Improvement in rheumatoid arthritis following application of an extracorporeal granulotrap column, G-1.

Patients with rheumatoid arthritis (RA) showed significantly (P < 0.01) increased numbers of granulocytes in their peripheral blood compared with normal donors and patients with osteoarthritis, and this finding correlated with interleukin-6 and C-reactive protein levels and active joint score. Then, 17 patients with RA were treated eight times in 4 weeks with a newly developed extracorporeal granulotrap column containing cellulose acetate beads (G-1 column). This column reduced granulocytes in the outflow blood by 50.2% compared with inflow counts. To evaluate the efficacy of G-1 therapy, 17 patients were followed for 12 weeks from the beginning of this therapy. The modified Lansbury index (LI) for monitoring RA activity significantly improved from a pretreatment mean score of 60.8% to a posttreatment score of 51.3%. The lowered scores were maintained up to 12 weeks after the initiation of therapy. Of the four LI items, tender and swollen joint scores showed the most significant improvement, with the tender joint score showing a particularly significant decrease throughout the study period. No serious side-effects were observed. These findings suggested that G-1 therapy was effective for RA.

Adult↗

Refined peptide HLA-B*3501 binding motif reveals differences in 9-mer to 11-mer peptide binding.

HLA-B*3501 is associated with subacute thyroiditis and fast progression of AIDS. An important prerequisite to investigate the T-cell recognition of HLA-B*3501-restricted antigens is the characterization of peptide-HLA-B*3501 interactions. In this study, peptide-HLA-B*3501 interactions were determined in quantitative peptide binding assays. The results were statistically analyzed to evaluate the influence of both anchor and nonanchor positions and the predictability of peptide binding. The binding data demonstrated that all anchor residues at position 2 and the C-terminus found in 9-mers functioned equally as anchors in 10-mers and 11-mers. These minimum requirements of peptide binding were refined by assessing positive and negative effects of nonanchor residues. Aliphatic hydrophobic residues at positions 3, 5, and 8 of 10-mers and position 3 of 11-mers significantly enhanced HLA-B*3501 binding. Similar effects rendered aromatic, bulky residues, acidic or polar residues of 11-mers at position 1 as well as at positions 4, 8, and 10, respectively. Negative effects were observed for residues carrying positively charged side-chains at position 7 of 11-mers. The refined HLA-B*3501 peptide binding motifs enhanced the identification of potential T-cell epitopes. The disparity between positive effects at the middle and C-terminal part (positions 5 - 8 and 10) of 11-mers and shorter peptides supports the extrusion of 11-mer residues at positions 5, 6, and 7, away from the HLA-B*3501 binding cleft.

Amino Acid Sequence↗

Large diffuse arteriovenous malformation affecting the right cerebral and cerebellar hemispheres: case report.

A cerebral vascular malformation was triggered in a 24-year-old man by left hemiparesis resembling transient ischemic attack. Cerebral angiography revealed slight dilation of the right anterior cerebral artery, middle cerebral artery, superior cerebellar artery, and posterior inferior cerebellar artery, as well as marked capillary blush and dilation of medullary veins involving the right cerebral hemisphere, especially the frontal lobe and cerebellar hemispheres. This vascular malformation, a clinical rarity, seemed to be in the same family as diffuse arteriovenous malformation or "medullary venous malformation." Single photon emission computed tomography showed a decline in cerebral blood flow in the right cerebral hemisphere, which was the probable cause of the left hemiparesis.

Adult↗