Adaptive response is differently induced depending on the sensitivity to radiation-induced cell death in mouse epidermal cells

We investigated the relationship between induction of radio-adaptive response and cell death in mouse normal and neoplastic epidermal cells. Mouse normal primary keratinocytes (PK), cancer-prone cells [v-rasHa-transfected mouse keratinocytes (ras-PK), and line 308 cells (mouse skin papilloma cells which have activated rasHa gene with A-to-T transversion at codon 61) were primed with a low dose of gamma-rays (0.01 Gy), and were challenged with a high dose (4 Gy) after a 4 or 7 h interval. The induction of cell death in PK was 2-10 times higher and was also more rapid in PK than in ras-PK or 308 cells. Low-dose pretreatment with a 4 h interval decreased cell death, and this adaptive response was prominent in PK, whereas it was less obvious in the cases of ras-PK and 308 cells. The response of each protein kinase C (PKC) isozymes to high-dose radiation, especially PKCalpha, PKCdelta, PKCepsilon, and PKCeta, were different between the normal and ras oncogene-activated neoplastic keratinocytes; translocation of these isozymes to membrane occurred more rapidly in normal than in neoplastic cells. Furthermore, low-dose pretreatment did not induce the translocation of PKCdelta in PK significantly more than in ras-PK and 308. Thus, the difference in the induction of radio-adaptive responses between mouse normal and neoplastic epidermal cells reflects difference in the rapidity of cell death, and responsiveness of PKC may affect this adaptive response.

Large cerebral infarction during praziquantel therapy in neurocysticercosis

BACKGROUND

Large cerebral infarction is a rare complication of neurocysticercosis. Endarteritis by inflammation of the leptomeninges is known to be its cause.

CASE DESCRIPTION

A 59-year-old man with known neurocysticercosis developed a large cerebral infarction during praziquantel therapy. A follow-up MRI obtained immediately after his cerebral infarction demonstrated notable decrease in the size of the cysts and more prominent enhancement around the peripheral margins of the cysts and the major vessels in comparison with the initial MRI. Cerebral angiography disclosed occlusions and narrowing of both internal carotid arteries at the supraclinoid portions, where multiple cysts were found on the MRI.

CONCLUSIONS

Findings in our patient strongly suggest that a secondary inflammation reaction caused by the destruction of the cysts might have enhanced the process of endarteritis. The possible deleterious effects of praziquantel therapy should be considered in the treatment of patients with subarachnoid cysticerci.

Pure motor hemiplegia with conjugate lateral gaze palsy in pontine lacunar infarction

The combination of pure motor hemiplegia and horizontal gaze palsy is a rare but identifiable lacunar syndrome. Among horizontal gaze palsies, one-and-a-half syndrome and abducens nerve palsy are reported to be associated with pure motor hemiplegia in pontine lacunar infarction. Although conjugate lateral gaze palsy is also hypothesized, pure motor hemiplegia with conjugate lateral gaze palsy has never been reported. We present a 75-year-old man who showed right hemiparesis and impaired left horizontal conjugate eyeball movement. Both the findings of the brain CT scan and those of the MRI study were consistent with a small infarction in the left midpontine tegmentum. Magnetic resonance angiography revealed no stenotic narrowing of the vertebrobasilar artery. Radiological findings suggested that pure motor hemiplegia with conjugate lateral gaze palsy, in our patient, might have been produced by the occlusion of a single penetrating branch of the basilar artery.