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Biomedical subjects

K Dohi

Publications and source records attributed to K Dohi.

At least 91 records · Page 5Linked to original sources
PubMed2000

Fatal severe vasospasm due to rewarming following hypothermia--case report.

A 37-year-old female died of cerebral vasospasm as a complication of rewarming following hypothermia therapy for severe head injury. She presented with severe consciousness disturbance and anisocoria after falling down a flight of stairs. Computed tomography (CT) revealed a right acute subdural hematoma and temporal contusion. Following surgery, mild hypothermia was started and rewarming was completed by the 11th day. Neurological examination showed no abnormalities, but intracranial pressure (ICP) suddenly increased and she manifested anisocoria on the 13th day. Repeat CT revealed a low density area in the right middle cerebral artery region and cerebral angiography showed diffuse narrowing of the main arterial trunks. A cerebrospinal fluid (CSF) sample was collected using an intraventricular ICP monitoring catheter. The CSF level of 8-hydroxy-2'-deoxyguanosine was elevated during the rewarming period, indicating substantial deoxyribonucleic acid (DNA) oxidation. She died on the 15th day due to uncontrollable ICP. Histological examination at autopsy of the narrowed artery found the waving phenomenon in the internal elastic lamina and invasion of inflammatory cells into the adventitia. These findings constitute the possible evidence that free-radical-mediated oxidative DNA damage may be important in the genesis of severe vasospasm due to rewarming following hypothermia.

Adult↗
PubMed2000

Neuropsychological changes after surgery for anterior communicating artery aneurysm.

Neuropsychological disturbances following surgery for anterior communicating artery aneurysms were analyzed in 26 patients (11 males, 15 females) using the Hasegawa dementia scale-revised (HDS-R) over a 3-year period. The patients were aged from 34 to 76 years (mean 54.1 years). Lesions in the frontal lobe were evaluated using computed tomography (CT). Twenty-three patients had symptoms over the course. Four patients had basal forebrain lesion, five had ventral frontal lesion, and 12 had no lesion. Patients with basal forebrain lesion and no lesion tended to show disorientation. The mean HDS-R score was 10.2 points in the patients with ventral frontal lesion, and 13.5 points in the patients with no lesion. These scores are within the range for dementia. The mean HDS-R score in patients with basal forebrain and striate lesions was over 25 points and beyond the range for dementia. Significant differences were observed in the HDS-R score between patients with ventral frontal lesion and basal forebrain lesion, and between patients with no lesion and basal forebrain lesion (p < 0.05). Recovery from neuropsychological disturbances was poorer in patients with ventral frontal lesion and no lesion compared to those with basal forebrain and striate lesions, and their symptoms tended to persist.

Adult↗
PubMed2000

[Successful treatment using detachable coils for traumatic carotid cavernous fistula as a complication of transsphenoidal surgery for a pituitary adenoma: a case report].

We report a case of a patient with traumatic carotid cavernous fistula (CCF) caused by transnasal-transsphenoidal surgery, who was successfully treated using detachable coils. A 47-year-old man was admitted to our hospital because of severe headache. He was confirmed to have a nonfunctioning pituitary adenoma with presellar-type sphenoid sinus. Cerebral angiography initially disclosed no vascular lesions. A transnasal-transsphenoidal adenomectomy was performed. When the anterior wall of the sphenoid sinus was dissected with a chisel, the chisel deeply stuck into the posterolateral part of the sinus. Profuse arterial bleeding was observed through the sphenoid sinus. The bleeding was stopped easily by compression and packing with bone wax. The operation was continued, the sellar floor was opened widely and the tumor was removed subtotally. The medial wall of the cavernous sinus was intact. Histological examination revealed a pituitary adenoma. Immediately after surgery, the patient noticed a bruit. He developed chemosis and abducent palsy on the right side. Cerebral angiography displayed a high-flow CCF, which was attributed to the carotid artery injury caused by the transnasal-transsphenoidal surgery. The CCF disappeared after two-staged embolization using detachable coils, 1st transvenous and 2nd transarterial. Ten months later, cerebral angiography showed persistent occlusion of the fistula, and the patient experienced no tumor recurrence. It is suggested that drilling is a safer procedure than using a chisel for dissection of a sphenoid sinus with incomplete pneumatization. Endovascular treatment using detachable coils proved useful to manage the CCF, an unusual complication of transsphenoidal surgery.

Adenoma↗
PubMed2000

Study on eight patients with malignant tumors after renal transplantation.

The high incidence of cancer after renal transplantation is now a critical concern since the graft survival rate has been improved extensively. We experienced 9 malignancies in 8 patients out of 168 recipients up to December 31, 1999 in our hospital, consisting of a case of gastric plasmacytoma and cases of cancer in the liver (2), thyroid (2), prostate (1), breast (1), sigmoid colon (1) and gall-bladder (1). Two patients were diagnosed as having tumors within 3 months after transplantation, suggesting post-transplant acceleration of growth of the latent tumors. The other patients were diagnosed at an average of 128 months, ranging from 84 to 263 months after transplant. Two patients died of gastro-intestinal bleeding and acute heart failure. Four patients died directly of progressive neoplasm within 3 months after diagnosis. These results suggest that the course of malignancies developing in post-transplant recipients is more aggressive than that expected in non-transplant patients, and it is very important to intensively follow long-term surviving cases to detect the malignant tumors as early as possible.

Adolescent↗
PubMed1999

Mutations in the RAD54 recombination gene in primary cancers.

Association of a recombinational repair protein RAD51 with tumor suppressors BRCA1 and BRCA2 suggests that defects in homologous recombination are responsible for tumor formation. Also recent findings that a protein associated with the MRE11/RAD50 repair complex is mutated in Nijmegen breakage syndrome characterized by increased cancer incidence and ionizing radiation sensitivity strongly support this idea. However, the direct roles of BRCA proteins and the protein responsible for NBS in recombinational repair are not clear though they are associated with the recombinational repair complexes. Since RAD51 forms a complex with other members of the RAD52 epistasis group and with BRCA proteins, it is reasonable to ask if alterations of members of the RAD52 epistasis group lead to tumor development. Here we describe missense mutations at functional regions of RAD54 and the absence of the wild-type RAD54 expression resulting from aberrant splicing in primary cancers. Since RAD54 is a recombinational protein associated with RAD51, this is the first genetic evidence that cancer arises from a defect in repair processes involving homologous recombination.

Adenocarcinoma↗
PubMed1999

A long-term culture of human hepatocytes which show a high growth potential and express their differentiated phenotypes.

The present study succeeded for the first time in cultivating for more than 2 months human normal hepatocytes which showed a high growth potential and expressed their differentiated phenotypes. Constituents of culture medium were critical for this culture, and the medium optimized for their growth contained fresh human serum, fetal bovine serum, Swiss 3T3-cell conditioned medium, L-ascorbic acid 2-phosphate, epidermal growth factor, nicotinamide, and dimethyl sulfoxide. Hepatocytes steadily replicated and formed colonies which continued to increase in size up to around 35 days. The number of hepatocytes in the most replicative colonies increased 17-fold during 31 days. Cells in colonies expressed normal differentiated hepatocytic phenotypes for as long as 35 days. These hepatocytes retained normal liver functions at least for 70 days such as to secrete albumin, and to metabolize lidocaine and D-galactose.

3T3 Cells↗
PubMed1999

Delayed neuronal cell death in the rat hippocampus is mediated by the mitogen-activated protein kinase signal transduction pathway.

Transient global ischemia caused by 5 min of cardiac arrest induced delayed neuronal cell death (apoptosis) in the CA1 region of the rat hippocampus. To characterize the molecular mechanisms that regulate apoptosis in vivo, the contributions to cell death of mitogen-activated protein kinase family members were examined in the hippocampal region after brain ischemia-reperfusion. Ischemia-reperfusion led to a strong activation of the JNK/SAPK (c-Jun NH2-terminal protein kinase/stress activated protein kinase), ERK (extracellular signal-regulated kinase), and p38 enzymes. These results with other previous studies suggest that the activation of JNK/SAPK in accordance with p38 contributes to the induction of apoptosis in CA1 neurons.

Animals↗
PubMed1999

Ruptured superior mesenteric artery aneurysm occurring in association with a heterotopic pancreas: report of a case.

Aneurysmal disease of the visceral arteries is found in only about 0.2% of the population, and the celiac trunk and superior mesenteric artery (SMA) are involved in less than 10% of all visceral aneurysms. We present herein the case of a 71-year-old woman who suffered rupture of a SMA aneurysm. Histological examination of the periarterial tissues which existed next to the aneurysm revealed a heterotopic pancreas. To the best of our knowledge, no other case of an SMA branch aneurysm presenting in association with a heterotopic pancreas has ever been described in either the Japanese or English literature. This is the first report to indicate that a heterotopic pancreas is a likely incidental factor predisposing to visceral aneurysms.

Aged↗
PubMed1999

Perioperative blood transfusion as a prognostic indicator in patients with hepatocellular carcinoma.

We studied the relation of perioperative blood transfusion and the outcomes in 175 patients with hepatocellular carcinoma (HCC) who underwent hepatic resection from 1986 to 1994 in our hospital. Hepatectomy was performed in 23 (13.1%) patients with and 152 (86. 9%) without blood transfusions. The cumulative cancer-free survival rates for patients who had received blood transfusion was significantly lower than that for patients who had not received blood transfusions (p = 0.003). Further examinations revealed a significant difference in cancer-free survival rates for stage I-II patients (n = 75) of HCC (p = 0.02) but not for stage III-IV patients (n = 56) (p = 0.06). Cox regression analysis for recurrence revealed that blood transfusion was the most significant prognostic indicator (p = 0.001) for recurrence in stage I-II patients but not in stage III-IV patients (p = 0.99). These results suggest that a perioperative blood transfusion may be a significant prognostic indicator for patients with HCC who had underwent hepatectomy, especially in stage I-II patients of HCC.

Adult↗
PubMed1999

Double cancer - hepatocellular carcinoma and intrahepatic cholangiocarcinoma with a spindle-cell variant.

Intrahepatic cholangiocarcinoma (ICC) with a spindle-cell variant is very rare. We report here a surgical patient who had double cancer - hepatocellular carcinoma (HCC) and ICC with a spindle-cell variant. In this 70-year-old man, who had a history of hepatic resection for HCC about 2 years previously, two large discrete masses were identified in the right lobe of the liver. A right lobectomy of the liver was performed. Pathological findings revealed that one tumor was a typical HCC, and the other was ICC with sarcomatous lesions. Immunohistochemical examinations of the sarcomatous lesions in ICC demonstrated that some of the spindle cells were positive for keratin, epithelial membrane antigen, and vimentin, but negative for S-100 protein, desmin, and actin. From these findings, we concluded that the sarcomatous lesions of ICC were not a true sarcoma, but sarcomatous transformation of cholangiocarcinoma cells, that is, a spindle-cell variant of ICC.

Aged↗
PubMed1999

Effect of cardiac arrest on brain weight and the permeability of the blood-brain and blood-spinal cord barrier to albumin and tumor necrosis factor-alpha.

Time-dependent changes in brain and spinal cord were studied in mice in a cardiac arrest model. A transient decrease in body weight and a prolonged decrease in brain weight occurred after arrest whereas spinal cord weight was unchanged. The permeability of the blood-brain barrier (BBB) to I131-albumin and I131 tumor necrosis factor-alpha (TNF) showed maximal, non-significant increases on day 5 after cardiac arrest, but the permeability of the blood-spinal cord barrier (BSCB) to both materials was unchanged with time. We conclude that selective weight loss occurs in the brain after cardiac arrest with the integrity of the BBB and BSCB remaining intact to serum proteins and minimal alteration in the blood to CNS transport of TNF.

Albumins↗
PubMed1999

Aneurysm of the distal anterior inferior cerebellar artery at the medial branch: a case report and review of the literature.

BACKGROUND: Distal aneurysms of the anterior inferior cerebellar artery (AICA) are rare. Most have been located at the cerebellopontine angle. Only three cases, including ours, located in the medial branch of the AICA have been reported in the literature. METHODS: A 55-year-old female presented with epilepsy that she experienced for the first time. Computed tomography and magnetic resonance imaging revealed no abnormality. Digital subtraction angiography (DSA) disclosed a rare aneurysm at the medial branch of the distal anterior inferior cerebellar artery. In the blood workup on her admission, a mild inflammatory sign was found, and bacterial aneurysm was suggested as the presumptive differential diagnosis. Repeated DSA was performed 3 months after admission, but the aneurysm did not disappear. She then underwent a suboccipital craniotomy in the prone position. RESULTS: The aneurysm was clipped and partially resected for the pathological examination. Histologic examination revealed a true aneurysm. She was discharged without neurological deficit. CONCLUSIONS: In this report, we summarize the previous cases and discuss the location and clinical manifestations of aneurysms of the AICA through a review of the literature.

Angiography, Digital Subtraction↗
PubMed1999

The effect of cardiac arrest on the permeability of the mouse blood-brain and blood-spinal cord barrier to pituitary adenylate cyclase activating polypeptide (PACAP).

Time-dependent changes in peptide transport system (PTS-6), which transports the 38 amino acid pituitary adenylate cyclase activating polypeptide (PACAP) across the blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB), were studied in mice in a cardiac arrest model. The permeability of the BSCB to radioactivity labeled I131 showed a reversible increase on Day 2-(24 h) after cardiac arrest. The BBB showed no such increase. The increase in BSCB permeability was primarily located within the thoracic region of the spinal cord. We conclude that the ischemia occurring with cardiac arrest results in a transient increase in PTS-6 activity located primarily in the thoracic region of the spinal cord.

Animals↗
PubMed1999

Increased urinary levels of adrenomedullin in patients with cystitis.

In this study, we examined urinary levels of adrenomedullin (AM) in 18 healthy volunteers and 18 patients with cystitis. We also compared urinary levels of AM in 11 patients with cystitis before and after antibiotic treatment. Urinary AM concentrations were measured by a radioimmunoassay specific for human AM. Urinary AM levels in patients with cystitis were significantly elevated compared with those of healthy volunteers and correlated positively with the number of urine leukocytes. By antibiotic treatment, urinary AM levels significantly decreased as compared with before the treatment. By RNA blot analysis of AM transcript, we detected significant levels of AM mRNA in canine urinary bladder and ureter. Intravenous administration of lipopolysaccharide elevated the AM mRNA level in the urinary bladder. These data suggest that infection and inflammation stimulate AM production in the urinary tract, which results in increased urinary AM levels in patients with cystitis. Based on these results, it is deduced that AM participates in the pathophysiology of cystitis, and its urinary level could be used as an index of the degree of cystitis.

Adrenomedullin↗