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Biomedical subjects

K Okayama

Publications and source records attributed to K Okayama.

34 records · Page 2Linked to original sources
PubMed1991

[CT study in primary low spinal fluid pressure syndrome].

CT findings in primary low spinal fluid pressure syndrome are studied on the basis of 3 cases. Case 1 was a 43-year-old male with a complicated bilateral isodense subdural hematoma (SDH). Case 2 was a 45-year-old female with a complicated bilateral high dense SDH. Case 3 was a 36-year-old female discharged without any complications after spinal fluid pressure normalized. Slight downward displacement of the brain under low spinal fluid pressure is shown as the narrowing of with a Sylvian fissures and infratentorial cisterns on CT. On the other hand in this syndrome with a complicated bilateral isodense SDH, in addition to this finding CT reveals distortion and narrowing of body of lateral ventricles, which may be the differential findings from this syndrome without complicated SDH. Under low spinal fluid pressure, bridging veins are more stretched by a downward displacement of the brain. And consequently they are easily insured and SDH is developed.

Adult↗
PubMed1990

[A case of primary low spinal fluid pressure syndrome complicated by bilateral subdural hematoma--study of the cerebrospinal fluid circulation].

A 43-year-old man with no history of trauma or neurosurgical procedure was admitted our hospital because of orthostatic headache made worse in upright position. Spinal fluid pressure was 0 mmH2O, and CT scan revealed wide cortical sulci and ventricles. In the 26th hospital day he had severe headache and CT scan revealed bilateral subdural hematoma, then neurosurgical procedure was done. About 2 months later, he was relieved of the headache and spinal fluid pressure returned to normal. We performed lumbar isotope cisternography and isotope choroid plexography in our case when low spinal fluid pressure and normalized pressure. Isotope cisternography revealed the radioactivity counts decreased rapidly in low pressure and normal in normal pressure. On the other hand isotope choroid plexography was almost no difference between low and normal pressure. Our data suggest that primary low spinal fluid pressure syndrome is not caused by hypoproduction, but by an undetectable leak from a minute tear in a spinal root sleeve or hyperabsorption at the spinal arachnoid membrane.

Adult↗
PubMed1989

[Interhemispheric visual information transfer in callosal agenesis].

It has been well established that acquired lesions of the corpus callosum such as surgical section bring about disturbances of interhemispheric transfer of visual information. In contrast, patients with callosal agenesis do not display these specific deficits. The mechanisms of this compensation have been postulated as follows; (1) bilateral development of language function, (2) exploitation of extracallosal commissure fibers such as the anterior commissure. Several studies have reported, however, minor disturbances of interhemispheric visual transfer in callosal agenesis, such as less efficient interhemispheric transfer of complex visual stimuli (Gott & Saul, 1978), slower reaction time in interhemispheric comparison of visual stimuli (Sauerwein & Lassonde, 1983), or deficits in spatial localization in the right hemi-field (Martin, 1985). In order to settle these issues, we have administered four kinds of tachistoscopic visual recognition tests on 4 patients with complete agenesis of the corpus callosum confirmed by magnetic resonance imaging (MRI). This technique enabled us to see the mid-sagittal plane of the corpus callosum and diagnose its total absence with much higher certainty and precision than previous studies employing computed tomography (CT) or pneumoencephalography. Case 1: A 41-year-old right-handed man visited us because of recurrent numbness in the four extremities. Neurological examination revealed no abnormalities. MRI has confirmed that the corpus callosum was totally lacking, and that the anterior commissure was normally visualized. Case 2: A 31-year-old right-handed man was referred to us for the treatment of partial complex seizure. Total agenesis and lipoma of the corpus callosum was diagnosed by MRI and reconstructed sagittal view of CT scan.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Comparison of the performance of anti-CD7 and anti-CD38 bispecific antibodies and immunotoxins for the delivery of saporin to a human T-cell acute lymphoblastic leukemia cell line.

We have investigated the cytotoxic performance of two different anti-CD7/anti-saporin BsAb's (HB2 x DB7-18 and Q1.1), three anti-CD38/anti-saporin BsAb's (OKT10 x RabSap, OKT10 x DB7-18 and Q4.1) and an anti-CD7 (HB2-Sap) and anti-CD38-saporin (OKT10-Sap) immunotoxin for delivering the ribosome inactivating protein (rip) to the human T-cell acute lymphoblastic leukemia cell line HSB-2. In the case of CD7 as target molecule the immunotoxin outperformed both anti-CD7 BsAb's being six times more effective than HB2 x DB7-18 and 98 times more so than Q1.1 at effectively inhibiting protein synthesis in a dose dependent manner. The chemically constructed HB2 x DB7-18 BsAb was more effective at inhibiting protein synthesis and cell growth in target HSB-2 cells in a dose dependent manner than the quadroma produced BsAb Q1.1. Both BsAb demonstrated a prozone effect used at concentrations above 0.1 nM though this was more pronounced for Q1.1 than for HB2 x DB7-18. The prozone effect was partially though not completely reversed by increasing the concentration of saporin in the system. In the case of CD38 as target molecule the anti-CD38 IT OKT10-Sap performed poorly, never actually achieving its IC50. Two BsAb's constructed with monoclonal anti-saporin Fab arms each recognizing a different epitope on the saporin molecule also performed poorly. In contrast the BsAb OKT10 x RabSap constructed with Fab derived from a rabbit polyclonal anti-saporin antiserum performed in a dose dependent manner achieving its IC50 at a concentration of 1.3 nM. This BsAb also exhibited a prozone effect. These results exemplify the importance of cross linking adjacent target molecules on the cell surface in order to achieve effective delivery of saporin to the cell interior.

ADP-ribosyl Cyclase↗