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Biomedical subjects

K Houkin

Publications and source records attributed to K Houkin.

At least 127 records · Page 7Linked to original sources
PubMed1991

Rebound alkalosis and persistent lactate: multinuclear (1H, 13C, 31P) NMR spectroscopic studies in rats.

Intracellular pH levels of infarcted brain determined by phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy disclosed a notable phenomenon. The acidotic brain pH seen in the acute stage of infarction was observed to rebound into the alkalotic range in the subacute phase before returning to the normal range in the chronic phase. This "rebound alkalosis" which was usually observed between the 24th and the 48th hour after experimental induction of infarction in rats was accompanied by significant lactate levels as detected by proton NMR spectroscopy. Analysis of the satellite methyl resonance of 13C-lactate using high-resolution proton NMR spectroscopy after 13C-glucose infusion indicated that no lactate was produced in the subacute phase of infarction and that the lactate detected during this phase must have been generated prior to this phase of infarction.

Alkalosis↗
PubMed1991

Acute aggravation of subdural effusion associated with pachymeningitis carcinomatosa: case report.

The authors present a case of acute aggravation of subdural effusion associated with pachymeningitis carcinomatosa. Microscopic examination of a surgical specimen revealed diffuse involvement of the dura mater by a metastatic adenocarcinoma in which the tumor cells invaded venules located in the areolar layer in particular. The rapid increase in capillary transmural pressure resulted in extravasation of plasma components, causing an increase in subdural effusion.

Adenocarcinoma↗
PubMed1991

Clinical application of proton magnetic resonance spectroscopy to cerebral ischemia.

Proton magnetic resonance spectroscopy (MRS) with the depth resolved surface coil spectroscopy technique and the 1331-2662 water suppression method was used to examine two cerebral ischemia patients and 10 normal volunteers. In all cases, N-acetyl-aspartate, creatine, phosphocreatine, and residual lipid were clearly observed. No lactic acid peak was observed in normal volunteers, but a large lactic acid peak appeared in the early stage of cerebral ischemia. This MRS abnormality was observed before abnormalities appeared in conventional imaging such as computed tomographic scanning and magnetic resonance imaging.

Adult↗
PubMed1991

[Longitudinal change of H-1 spectroscopy in cerebral infarction].

Longitudinal change of the proton spectroscopy was observed in 2 cases of cerebral infarction. Proton spectra was acquired utilizing stimulated echo acquisition mode (STEAM). In acute stage, the increase of lactic acid and decrease of N-acetyl-aspartic acid (NAA) was observed prior to the appearance of abnormality in imagings such as magnetic resonance imaging and computer tomography. The increase of lactic acid was observed in subacute stage and chronic stage (in severe case). The decrease of NAA persisted in chronic stage. The increase of lactic acid and decrease of NAA indicate a damage of the ischemic tissue. The degree of the decrease of the NAA seems to be a reasonable indicator of the viability of the damaged tissue. The proton spectroscopy is a powerful modality for the evaluation of the extent of tissue damage caused by the ischemic insult.

Aged↗
PubMed1991

[Three-dimensional MR brain image using volume rendering method].

3-dimensional image reconstructed from the data of computer tomography has provided useful informations for the pre-operative evaluation in the field of neurosurgery and plastic surgery. However CT has failed to visualized the 3-dimensional surface image of the central nervous system. On the other hand the progress of high-speed data acquisition technique and 3-dimensional fourier transformation has enabled the practical 3-dimensional image using magnetic resonance imager. However for the visualization of a pure surface image of the brain and spinal cord a sophisticated method and special image work station has been necessary. The authors describe a technique for the pure surface image of the brain and spinal cord using a normal mini-computer system and magnetic resonance imager. This image has a good correlation to the macroscopic anatomical brain surface (sulci and gyri).

Brain↗
PubMed1991

[Stab wounds of the spinal cord by a kitchen knife: report of a case].

A case of spinal cord injury due to stab wounds by a kitchen knife is presented. A 41-year-old male was hospitalized because of spinal cord injury resulting from stab wounds inflicted with a kitchen knife in the posterior cervical area. Neurological examination on admission showed paraplegia, disappearance of deep tendon reflex in both lower extremities, sensory disturbance below T1 level, left Horner's syndrome and urinary disturbance. In addition to these symptoms cerebrospinal fluid was leaking from the wounds. An emergency operation was performed. After laminectomy of C7 and T1, we found that the spinal cord was almost completely split at C7/T1 level. Dural plasty was performed. Neurologically, sensory disturbance was slightly improved at 4 months after the injury. Initial MRI (TR: 200 msec, TE: 20 msec) revealed high intensity at C7/T1 level which was damaged by the kitchen knife. MRI 5 months after the injury revealed low intensity on T1 weighted imaged, high intensity on T2 and proton weighted image. The occurrence of the spinal cord injury due to stab wounds by a kitchen knife is very rare in Japan. MRI is useful in the diagnosis of stab wounds of the spinal cord.

Adult↗
PubMed1990

Persistent high lactate level as a sensitive MR spectroscopy indicator of completed infarction.

Serial proton (1H) and phosphorus-31 (31P) magnetic resonance (MR) spectroscopy of cerebral infarction was performed in rats to assess the sensitivity of these techniques for use in clinical cerebral infarction. In this experimental chronic infarction model, 31P spectroscopy tended to return to a "normal" pattern within 24 hours after induction of infarction in spite of pathologically proven completed infarction and, therefore, appeared not to be sensitive enough for clinical application. On the other hand, proton spectroscopy invariably showed persistent high lactate levels and was capable of distinguishing completed infarction from reperfused recovered brain. Persistent high lactate levels appear to be a good MR spectroscopic indicator of completed infarction.

Animals↗
PubMed1990

[Proton and phosphorus-31 nuclear magnetic resonance spectroscopy in experimental cerebral infarction in rats].

Longitudinal study of metabolic change after cerebral infarction was done using nuclear magnetic resonance spectroscopy (MRS). Localized completed infarction model induced by intra-cranial ligation of the middle cerebral artery and extra-cranial ligation of common carotid artery in rats was utilized. In acute study the proton MRS revealed a sharp increase of lactic acid but the phosphorus -31 MRS did not show prominent changes. This increase of lactic acid persists 24 hours after the induction of infarction. In chronic study the spectroscopic pattern of the infarcted brain showed minimum difference from the control normal brain. However the signal intensity of phosphomonoester was significantly higher in the infarcted brain. Our study in acute phase suggests that the proton MRS is a sensitive probe to detect an early metabolic deterioration induced by ischemic insult. And the increase of phosphomonoester in chronic infarcted brain may imply that a gliosis seen in chronic infarction has a metabolic resemblance to neonate brain and neoplasm.

Animals↗
PubMed1989

Intrauterine fetal brain NMR spectroscopy: 1H and 31P studies in rats.

Fetal brain metabolism was investigated in utero noninvasively using multinuclear nuclear magnetic resonance spectroscopy in rats at two representative prenatal stages: early (17-18 days) and late (20-21 days) stages. Phosphorus-31 (31P) spectroscopy revealed that phosphocreatine is significantly lower in the early stage and increases to the level of early neonates by the late prenatal stage. Intracellular pH at the early stage was found to be strikingly high (7.52 +/- 0.21) and decreased to a level similar to that of neonates by the late stage (7.29 +/- 0.07). Phosphomonoester levels at both stages were similar to the values reported for early neonates. Water-suppressed proton (1H) spectroscopy demonstrated a distinctive in vivo fetal brain spectral pattern characterized by low levels of N-acetyl aspartate and high levels of taurine. High-resolution proton spectroscopy and homonuclear chemical-shift correlate spectroscopy of brain perchloric acid extracts confirmed these in vivo findings. In vitro 31P spectroscopy of acidified chloroform methanol extracts showed the characteristic membrane phospholipid profiles of fetal brain. The phosphatidylethanolamine (PE)-to-phosphatidylcholine (PC) ratio (PE/PC) did not show significant changes between the two stages at 0.40 +/- 0.11, a value similar to that of early neonates.

Animals↗
PubMed1989

Cortical spectroscopy: localized spectroscopy of the cerebral cortex in rats.

A method for obtaining nuclear magnetic resonance (NMR) spectroscopic signals confined to the cerebral cortex in rat using a cortical coil constructed based on the principles of the zig-zag coil is described. We obtained 31P NMR spectra of normal cerebral cortex and cold-induced injured cortex using this cortical coil. The cortical coil clearly demonstrated an increase in inorganic phosphate (Pi) confirmed to cerebral cortex which, by contrast, the conventional planar surface coil failed to detect. There are significant metabolic differences between cortex and subcortical tissues. The technique described here, capable of assessing cortical metabolism in vivo without contamination by the underlying tissue, has substantial application to studies of cerebral metabolism.

Animals↗
PubMed1989

31P magnetic resonance spectroscopy of chronic cerebral infarction in rats.

The chronological changes in the pattern of 31P magnetic resonance spectroscopy (MRS) associated with cerebral infarction were studied in rats. 31P MRS of chronic infarction (1 month after induction of infarction) clearly showed a pattern distinct from that of normal brain. In chronic infarction, the relative phosphomonoester (PME) level was found to be significantly higher and relative phosphocreatine (PCr) level significantly lower compared to normal brain. The intracellular pH and the relative inorganic phosphate (Pi) level did not show any significant differences. Histological examination indicated that the 31P MRS pattern of chronic infarction reflects gliosis.

Animals↗
PubMed1986

Separation of cerebral embolism with angiographical criteria--a preliminary report.

Total of 35 cases of cerebral arterial occlusion were studied with repeated angiography. Cerebral embolisms (E group; 18 cases) were distinguished from cerebral thrombosis (T group; 17 cases) by angiographical criteria: recanalization of occluded arteries of demonstration of embolus with distinct contour. Clinical findings and laboratory data of each group were compared and thought to be well separated. Appropriateness and significance of these criteria are discussed.

Aged↗
PubMed1984

[Mixed pial-dural arteriovenous malformation. Case report].

The authors report a case of mixed pial-dural arteriovenous malformation (mixed pial-dural AVM), which had feeders from both cortical branches of the internal carotid artery and middle meningeal artery of the external carotid artery. A clinical course of this case is presented and literatures are reviewed. Moreover the authors stress the rete mirabile anastomoses as an important factor in the genesis of the mixed pial-dural AVM. The patient, 30-year-old female, suddenly suffered from a severe headache on December 31, followed by gradual deterioration of consciousness. She was admitted to Otaru Second City Hospital one hour after the episode and neurological examination disclosed moderate confusion, right hemiparesis and neck stiffness. CT scan revealed a massive hematoma in the bilateral ventricles and left parietal lobe and skull plain film showed an enlargement of the groove of the middle meningeal artery. Angiography revealed a mixed pial-dural AVM in the left parietal lobe, which had feeders from both cortical branches of the left internal carotid artery and middle meningeal artery of the left external carotid artery. Two weeks later the admission, an operation was performed. A ligation of the external carotid artery at the neck was performed before a craniotomy, and the bleeding from the dura was minimal, and the AVM in the parietal lobe was removed completely. The patient recovered satisfactorily without any trouble and she was discharged with only a mild weakness at the right side. The clinical finding of the mixed pial-dural AVM is discussed and the rete mirabile anastomoses is emphasized as an important factor in the genesis of the mixed pial-dural AVM.

Adult↗