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Biomedical subjects

H Caner

Publications and source records attributed to H Caner.

48 records · Page 3Linked to original sources
PubMed1991

The role of lipid peroxidation in the genesis of vasospasm secondary to subarachnoid hemorrhage.

The aim of this study is to find out the possible trigger role of lipid peroxidation in vasospasm. Haemoglobin-free washed erythrocyte membranes (erythrocyte ghost) corresponding to 2.5 mg membrane protein was mixed with 0.5 umol NADPH 3 umol ADP, 4 umol ferrous sulphate and injected into the cisterna magna of cats to stimulate lipid peroxidation in vivo (Group 1). The second group was injected lml/kg whole blood and the control group 1 ml/kg saline. Angiographic studies revealed significant vasospasm in five cats in group 1. Severe vasospasm was seen in six cats in group 2. A significant increase in lipid peroxidation was observed in groups 1 and 2, compared to the control group. These results may suggest that free radical products may play an important role in the complex genesis of vasospasm in subarachnoid haemorrhage.

Angiography↗
PubMed1990

The distribution pattern of the sympathetic nerve fibers to the cerebral arterial system in rat as revealed by anterograde labeling with WGA-HRP.

To clarify the projection route and the expansion of the terminal plexus of the sympathetic nerve fibers innervating the cerebral arterial system in rat, we labeled the postganglionic fibers originating in the superior cervical ganglion and traced their entire course by anterograde labeling with wheat germ agglutinin-horseradish peroxidase. Sympathetic innervation of the internal cerebral artery by labeled fibers actually began just at the portion where it enters the intradural space, and innervated it up to the small pial arteries located in the subarachnoid space, but not the intracerebral arterioles. On the main arteries in the circle of Willis, bundles of nerve fibers ran parallel to the long axis of the vessels and branched perpendicularly their terminal twigs with regular intervals to form a rib-structure pattern. On the arterial branches derived from the circle of Willis, a fine nerve bundle and delicate terminal axons formed a meshwork instead of a rib-structure pattern. These observations confirmed the existence of differences in the distribution pattern of the nerve plexus, which strongly affects the strength and quality of vasoconstriction by sympathetic activation in each level of the cerebral arterial system.

Animals↗
PubMed1990

Appearance of retrogradely labeled neurons in the rat superior cervical ganglion after injection of wheat-germ agglutinin-horseradish peroxidase conjugate into the contralateral ganglion.

Injection of wheat-germ agglutinin-horseradish peroxidase conjugate (WGA-HRP) into the superior cervical ganglion (SCG) of the rat results in accumulation of WGA-HRP in sympathetic postganglionic neurons in the contralateral SCG. The sympathetic pathways involved and the mechanism underlying the labeling were investigated. The labeling in neurons in the contralateral SCG was apparent 6 h after injection and increased in intensity with longer survival times. The number of labeled neurons reached 1300 at 72 h after the injection. Transection of the external (ECN) or internal carotid nerves (ICN) resulted in considerable reduction in the number of labeled neurons. Combined transection of both ECN and ICN virtually eliminated labeling in the contralateral SCG. This provides strong evidence that these two nerves are the major pathways for WGA-HRP transport out of the SCG. No labeling was observed in the contralateral SCG following injection of horseradish peroxidase (HRP). Therefore, it seems unlikely that a direct nerve connection exists between the bilateral ganglia. Instead, the labeling of contralateral SCG neurons appears to depend on the transneuronal transport capacity of WGA-HRP, which conveys the marker in an anterograde direction along the postganglionic fibers to terminals in sympathetic target organs, and then delivers it transneuronally to contralateral SCG neurons. We suggest that the sympathetic nerve fibers originating in the bilateral SCGs run intermingled and are in close contact in their peripheral target organs.

Animals↗
PubMedDate not supplied

Cerebral Dermabacter hominis abscess.

Dermabacter species are commonly isolated from the skin and other body sites but rarely show pathogenicity in humans. A case of Dermabacter hominis cerebral abscess is reported which presented as a contrast-enhancing intracranial mass in a renal transplant patient.

Adult↗
PubMedDate not supplied

Nonsuture closure of arterial defect by vein graft using isobutyl-2-cyanoacrylate as a tissue adhesive.

Nonsuture repair of intracranial blood vessel is still a challenging issue in neurosurgery. In this experimental study isobutyl-2-cyanoacrylate was used for nonsuture repairing of carotid artery to observe its histotoxicity. Isobutyl-2-cyanoacrylate was dropped over the edge of defect on carotid artery of rat under the surgical microscope and jugular vein was placed to cover the defect. Rats were divided in 6 group according to postoperative survival period (2, 5, 7, 14, 21, 28 days respectively). The carotid arteries were patent of all rats according to angiography and autopsy specimen. Histopathological results showed that: the changes are mainly inflammatory respons +, there was no necrotic tissue at any time the healing progress and no significant differences in the vein graft. Therefore isobutyl-2-cyanoacrylate is considered helpful and safe adhesive material for the nonsuture repair of blood vessel.

Animals↗
PubMedDate not supplied

Pre and postoperative assessment of regional cerebral blood flow in hydrocephalus by 99mTc-hexamethyl-propylenamine oxime SPECT.

Cerebrovascular changes resulting from hydrocephalus still remain to be investigated. It has been suggested that hydrocephalus distorts the large feeding arteries and that the collapse of capillaries results in decreased cerebral blood flow. This clinical study was designed to evaluate the effect of shunting on regional cerebral blood flow in patients with obstructive hydrocephalus of varying duration. Technetium-99m hexamethyl propyleamine oxime (99mTc-HMPAO) was used to measure the cerebral perfusion, semiquantitatively, since the pattern of its distribution in brain is somewhat similar to that of regional cerebral blood flow (rCBF), and the pre and postoperative semiquantitative rCBF values of each lobe were calculated. Fifteen patients (8 F, 7 M) underwent both CT and single photon emission tomography (SPECT) using 99mTc-HMPAO examination before and 1 week after shunting. Mean percentage of all lobes were calculated by subtracting the preoperative mean rCBF of all lobes from the corresponding postoperative values. The patients were classified into 3 groups according to the mean percentage of all lobes. Group A: showed a marked increase in mean cortical blood flow (+ 16.00 +/- 2.9%), group B: a moderate increase (11.27 +/- 4.8%), and in group C: there was the least improvement in mean cortical blood flow (+ 1.17 +/- 2.7%). The mean duration of hydrocephalus of group A, group B and group C was 5 +/- 0.5 weeks, 8 +/- 1 weeks and more than 12 weeks, respectively. Psychological testing and clinical observation of the daily activities of the patients postoperatively showed some correlation with increased rCBF and clinical improvement.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Thrombosis of intracranial venous sinuses: aetiology, clinical findings and prognosis of 56 patients.

Cerebral venous thrombosis may occur as a complication of infectious and noninfectious processes. In this study 56 patients with angiographically proven cerebral venous thrombosis (CVT) affecting dural sinuses are being reported. Sixty-one percent of the patients were female and 60% were below 30 years of age. Sixty-four percent of the patients had lateral sinus thrombosis and in 26.8% of the cases a septic focus has been found. The diagnosis is established by serial angiography and clinical findings. CVT is not a rare disease while the clinical diagnosis may be difficult because of the variable modes of onset. As the CT findings are found to be non-specific, angiography remains as the best diagnostic tool. Early diagnosis, controlled intracranial pressure, and appropriate antibiotic treatment may reduce the mortality and morbidity rates due to CVT.

Adult↗
PubMedDate not supplied

Cerebellar infarction: computed tomography, magnetic resonance and IMP-single photon emission tomography findings.

In this report, a rare case of a child with cerebellar infarction (CI) confirmed by vertebral angiography, magnetic resonance imaging (MRI), computed tomography (CT) and N-isopropyl-p123-I-iodoamphetamine single photon emission tomography (IMP-SPECT) is presented. It was concluded that although all imaging modalities could demonstrate CI, MRI is superior to the other methods because of its fine display of anatomical detail, its lack of bony artifacts and its ability to show infarction in early stages.

Cerebellum↗
PubMedDate not supplied

Diagnostic value of computed tomography in spinal and lateral recess stenosis, preoperatively and for long-term follow-up: a prospective study in 50 cases.

Preoperative measurements of lateral recess, anterior-posterior diameter of the spinal canal and interpedincular distance were made in 50 patients with low back pain. The results were compared with the surgical findings. The patients were followed up for two years. CT findings and clinical results were evaluated to determine whether preoperative CT could provide any evidence of failed spinal surgery in patients with recurrent symptoms.

Adult↗