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C Kitanaka

Publications and source records attributed to C Kitanaka.

At least 37 records · Page 2Linked to original sources
PubMed1996

Chronic encapsulated expanding hematoma in association with gamma knife stereotactic radiosurgery for a cerebral arteriovenous malformation. Case report.

The authors report a rare case of a patient with a chronic encapsulated expanding hematoma and progressive neurological deterioration who presented 2 years after gamma knife radiosurgery for a cerebral arteriovenous malformation (AVM). A tough capsule containing multiple layers of organized hematoma resulting from previous bleeding was confirmed surgically. Histological examination revealed that the capsule consisted of a dense collagenous outer layer and a granulomatous newly vascularized inner layer with marked fibrosis. Hemosiderin deposits were frequently observed in the inner layer, which suggested recurrent minor bleeding from fragile vessels in this layer. An AVM was found in the hematoma, which had degenerated as the result of radiosurgery. A cross-section of the abnormal vessels showed various stages of obliteration due to intimal hypertrophy. The clinical course, radiological features, and histological findings in this case were compatible with those of previously reported chronic encapsulated hematomas. A possible mechanism of hematoma formation and its expansion are discussed.

Adult↗
PubMed1996

[Apoptosis induced by myc family genes].

Recent studies have revealed that c-Myc is involved not only in cellular transformation but also in apoptosis induction. However, the intronless myc family genes such as s-myc, N-myc2, mycL2 lack transforming ability and retain only apoptosis inducing activity. Although much remains to be clear regarding the molecular mechanism of apoptosis induction by myc gene expression, our recent results suggest that the intronless myc genes significantly differ from that of the c-myc gene in their requirement for wild-type p53 activity in apoptosis induction. We introduce here recent reports on Myc-mediated apoptosis and discuss its molecular mechanism.

Animals↗
PubMed1996

Apoptosis in cancer.

Apoptosis is a genetically encoded cell death program and plays an important role in the regulation of both normal and malignant processes. Recently, many factors involved in the control of apoptosis have been isolated and characterized, and thereby studies on the molecular mechanism of the signaling pathway of apoptosis have made rapid progress. In this article, we discuss the role of apoptosis in carcinogenesis and the possible ways to apply apoptosis to cancer therapy.

Apoptosis↗
PubMed1995

Functional prognosis after treatment of spinal radiculomeningeal arteriovenous malformations.

BACKGROUND: We performed surgical treatment successfully in six patients with spinal radiculomeningeal arteriovenous malformation (AVM); however, only four patients showed improvement of gait function postoperatively. METHODS: These experiences prompted us to review the clinical findings and their possible association with the functional outcome in 33 reported cases of radiculomeningeal AVM together with those in our six patients. RESULTS: Statistical analysis revealed that the duration from onset of symptoms until diagnosis, the age at the time of treatment, the condition of the deep tendon reflexes (DTR) in the lower extremities, as well as the severity of both gait and urinary disturbance before treatment were significantly correlated with the functional outcome. CONCLUSIONS: A patient under 70 years old, who is treated within 2 years 6 months after the onset, whose gait or urinary disturbance is slight or moderate, and without absence of DTR in the lower extremities, is expected to have a good functional prognosis after treatment.

Aged↗
PubMed1995

Clinical features of progressive lacunar infarction--retrospective analysis of patients with motor syndromes.

The clinical features of progressive lacunar infarction were analyzed in 20 patients with lacunar infarction. Seven of the 20 patients experienced paresis progression and the remaining 13 patients had a stable course. The mean age of progressive lacunar infarction patients (78.6 +/- 4.30 yrs) was significantly higher than that of stable lacunar infarction patients (65.1 +/- 7.68 yrs) (p < 0.01). Patients presenting with pure motor stroke were more likely to have progressive stroke (7/13) than those presenting with sensorimotor stroke (0/7) (p < 0.05). Paresis aggravation began on Day 1 and ceased on Day 2 in most patients. Progressive paresis began to improve after reaching the nadir. Hemiparesis was only slightly worse after 1 month compared with that on admission. Older patients are more likely to have a progressive course. Paresis progression in lacunar patients does not preclude the possibility of recovery and is not necessarily associated with a poor prognosis.

Aged↗
PubMed1995

s-Myc acts as a transcriptional activator and its sequence-specific DNA binding is required for induction of programmed cell death in glioma cells.

We previously reported that s-Myc expression effectively induces programmed cell death (PCD) by apoptosis in glioma cells that express only mutated p53. To determine the molecular mechanism of s-Myc-induced PCD, we examined the correlation between transcriptional activation of s-Myc and its ability to induce PCD. Using a reporter plasmid having an upstream promoter region containing four repeats of the hexanucleotide CACGTG, we found that s-Myc can activate transcription of a reporter gene from this plasmid. Two mutated forms of s-Myc protein, s-MycCKII and s-MycmBR, were created. While s-MycCKII whose casein kinase (CK) II cognate sequence was restored in the internal acidic domain activated transcription as efficiently as wild-type s-Myc and induced PCD in glioma cells, s-MycmBR having a mutated basic region unable to bind the CACGTG motif did not. These findings suggest that transactivation activity of s-Myc through sequence-specific DNA binding may be indispensable for induction of PCD but that lack of a CK-II cognate sequence in the internal acidic domain may have little effect on these functions of s-Myc.

Journal Article↗
PubMed1994

Malignant brain stem hyperthermia caused by brain stem hemorrhage.

BACKGROUND: We report two cases of brain stem hemorrhage characterized by severe hyperthermia, rhabdomyolysis, acute renal failure, and a rapidly fatal course. METHODS: A 55-year-old man and a 65-year-old man were admitted with coma-producing brain stem hemorrhage accompanied by hyperthermia. Both underwent ventricular drainage. RESULTS: Within 1 day of onset, both patients developed hyperthermia of over 41 degrees C, increased serum creatine phosphokinase (CPK) level indicating rhabdomyolysis, and acute renal failure. One patient died on the second day and the other on the third day after onset despite supportive treatment. CONCLUSIONS: These cases of brain stem hemorrhage with fulminant hyperthermia should be distinguished from those with simple hyperthermia. They may represent a kind of malignant hyperthermia, in which case dantrolene sodium might be beneficial. Monitoring serum CPK levels would be of help in making the diagnosis early in the course.

Aged↗
PubMed1994

Magnetic resonance imaging study of intracranial vertebrobasilar artery dissections.

BACKGROUND AND PURPOSE: The purpose of this study is to demonstrate the magnetic resonance features of intracranial vertebrobasilar artery dissections and to determine the potential and limitations of magnetic resonance imaging in their diagnosis. METHODS: We studied five consecutive patients with angiographically verified intracranial vertebrobasilar artery dissection with magnetic resonance imaging (0.5 T) in regard to the shapes of the intramural hematoma and the chronological change of its signal intensity. We also estimated the sensitivity of magnetic resonance imaging for diagnosing dissection. RESULTS: We observed intramural hematoma in four patients on the first magnetic resonance scan and in all five patients during the course of the study. The shapes of the intramural hematomas were curvilinear, crescentic, "bamboo-cut," "band-like," and spotty. The intensity of the intramural hematoma varied according to its age. On the T1-weighted and the proton images, the intramural hematomas appeared isointense to slightly hyperintense in the first few days and became hyperintense thereafter. The intramural hematomas became isointense or unrecognizable 2 months after onset. The T1-weighted image and the proton images were superior to the T2-weighted image in demonstrating the intramural hematomas. CONCLUSIONS: Magnetic resonance imaging is a sensitive tool for diagnosing intracranial vertebrobasilar artery dissection, particularly in the subacute to early chronic stage. Magnetic resonance imaging is complementary to angiography in that it can directly visualize intramural hematomas.

Adult↗
PubMed1994

Intracranial vertebral artery dissections: clinical, radiological features, and surgical considerations.

We reviewed 24 patients with intracranial vertebral artery dissections treated during the last 12 years. Sixteen patients were admitted with subarachnoid hemorrhage (SAH) and 8 did not have SAH. The mean age at the time of onset was 50.0 years. Male preponderance was noted. Among 21 patients with acute onset, 6 (29%) experienced prodromal neck pain and 3 (60%) of 5 SAH patients showed nuchal stiffness when examined within 6 hours of onset. The preoperative angiographical findings were uniform in SAH cases in contrast to the varied angiographical findings seen in non-SAH cases. So-called pearl and string sign was observed in most SAH cases, but the "string" was often so short and wide that the term "constriction" appeared more suitable. From intraoperative observations, the angiographical point of constriction seemed to represent the proximal or distal end of dissection. As for treatment, 19 patients underwent 20 surgeries. Trapping was performed in eight surgeries, base clipping was performed in five, and proximal clipping was performed in seven. Both trapping and base clipping prevented further bleeding, but trapping was associated with a high rate of postoperative lower cranial nerve palsy. Postoperative neurological complications were less frequent after proximal clipping, but subsequent postoperative bleeding occurred in one patient treated by this technique. The overall long-term outcome in the surgically treated cases in our series was favorable, but most patients suffered from various degrees of uncomfortable dysphagia or hoarseness for some period after surgery. It was also noted that, in half of the disabled cases, the major disability was attributable to lower cranial nerve palsy and respiratory troubles that developed postoperatively.

Adult↗
PubMed1994

Nonsurgical treatment of unruptured intracranial vertebral artery dissection with serial follow-up angiography.

The question of whether unruptured intracranial vertebral artery dissections should be treated surgically or nonsurgically still remains unresolved. In this study, six consecutive patients with intracranial vertebral artery dissection presenting with brain-stem ischemia without subarachnoid hemorrhage (SAH) were treated non-surgically with control of blood pressure and bed rest, and five received follow-up review with serial angiography. No further progression of dissection or associated SAH occurred in any of the cases, and all patients returned to their previous lifestyles. In the serial angiograms in five patients, the findings continued to change during the first few months after onset. Four cases ultimately showed "angiographic cure," while fusiform aneurysmal dilatation of the affected vessel persisted in one case. In one patient, arterial dissection was visualized on the second angiogram despite negative initial angiographic findings. These results indicate that intracranial vertebral artery dissection presenting without SAH can be treated nonsurgically, with careful angiographic follow-up monitoring. Persistent aneurysmal dilatation as a sequela of arterial dissection seemed to form a subgroup of fusiform aneurysms of the posterior circulation. These aneurysms may be prone to late bleeding and may require surgical treatment.

Adult↗
PubMed1994

Precocious puberty in a girl with an hCG-secreting suprasellar immature teratoma. Case report.

Although precocious puberty is common in boys with human chorionic gonadotropin (hCG)-secreting brain tumors, it is extremely rare in girls. The authors describe a 6-year-old girl with an hCG-secreting suprasellar immature teratoma who presented with diabetes insipidus, increased intracranial pressure, and precocious puberty. On admission, breast budding was observed. The serum hCG level was 1230 mIU/ml. Both luteinizing hormone (LH) and follicle-stimulating hormone (FSH) remained below detectable levels, even after gonadotropin-releasing hormone stimulation. Serum estrogen and androgen were moderately elevated. After chemotherapy, breast budding disappeared with normalization of serum hCG. It has been believed that hCG does not produce precocious puberty in girls in the absence of FSH, and this has been used as an explanation for the rarity of precocious puberty in girls with hCG-secreting brain tumors. However, it has also been reported that hCG has not only LH activity but also intrinsic, although weak, FSH-like activity. In the present case, this FSH-like activity was considered to have played a role in the development of precocious puberty. It is speculated that a very high level of serum hCG can produce precocious puberty in girls. The rarity of intracranial germ-cell tumors with a high potential of hCG secretion may be one of the reasons why hCG-induced precocious puberty is uncommon in girls.

Brain Neoplasms↗
PubMed1993

Intradural, purely extramedullary hemangioblastoma of the spinal cord--case report.

An unusual, purely extramedullary hemangioblastoma of the spinal cord occurred in a 59-year-old female. Myelography revealed a filling defect at the Th6 level, and computed tomographic myelography demonstrated an extramedullary intradural isodense mass at the same level. The mass was homogeneously enhanced on postcontrast computed tomographic scans. T1-weighted magnetic resonance imaging showed an isointense mass, homogeneously enhanced by contrast medium. The tumor was removed en bloc.

Diagnosis, Differential↗
PubMed1992

Retroflexion of holoprosencephaly: report of two cases.

Two cases of retroflexed holoprosencephaly are presented. Reports of nine cases of retroflexion were available in the literature. Case analysis indicates that retroflexion results from subdural fluid collection. The incidence of retroflexion in holoprosencephaly was apparently higher than that of ordinary subdural hygromas. Possible explanations for this high incidence are given. The clinical significance and management of retroflexion are touched upon.

Brain↗
PubMed1992

Avellis syndrome after minor head trauma: report of two cases.

Avellis syndrome is a rare condition that usually occurs in association with infarction of the medulla oblongata or mass lesions around the jugular foramen; this syndrome has rarely been reported after trauma. Two cases of Avellis syndrome that occurred following minor head trauma are presented. The mechanism by which Avellis syndrome is produced is briefly discussed. The relative resistance to damage of the spinal accessory nerve was thought to play an important role in producing the peripheral type of Avellis syndrome. The outcome was favorable in both cases.

Adult↗
PubMed1992

Secondary malignant lymphoma of the central nervous system with delayed high uptake on 123I-IMP single-photon emission computerized tomography. Case report.

A case of secondary central nervous system (CNS) lymphoma with high uptake in the delayed image of N-isopropyl-[123I]-p-iodoamphetamine (125I-IMP) single-photon emission computerized tomography (SPECT) is presented. Previous to this report, only six cases of brain tumor with high uptake on the delayed 123I-IMP SPECT scan have been reported, two of which were CNS malignant lymphomas. Of 19 brain tumors examined with 123I-IMP SPECT at Kameda General Hospital, this case was the only one that showed high uptake in the delayed image. These data imply that 123I-IMP SPECT, which has now become rather obsolete as a tumor-imaging method, can be useful in diagnosing CNS malignant lymphoma.

Adult↗