Induction of oxidative DNA base damage in human skin cells by UV and near visible radiation

The premutagenic oxidative DNA base damage, 7,8-dihydro-8-oxoguanine, is induced in human skin fibroblasts by monochromatic radiation ranging from a UVB wavelength (312 nm) up to wavelengths in the near visible (434 nm). The oxidative damage is not generated by absorption of radiation in DNA but rather by activation of photosensitizers generating genotoxic singlet oxygen species. The spectrum for the yield of the oxidative damage in confluent, non-growing, primary skin fibroblasts shows that it is UVA (above 334 nm) and near visible radiations which cause almost all of this guanine oxidation by natural sunlight in the fibroblast model. We estimate that the total amount of oxidation of guanine induced by sunlight in fibroblasts in the epidermis of the skin equals or exceeds the amount of the major type of direct DNA damage, cyclobutane pyrimidine dimers. In rapidly dividing lymphoblastoid cells, no oxidative guanine damage was induced. However, in melanoma cells almost as much damage as in non-growing fibroblasts (1.1 per 10(4) guanine bases after 1200 kJ/m2 UVA) was found. We conclude that oxidative DNA base damage can probably contribute to the induction of both non-melanoma and melanoma skin cancer by sunlight.      

Physiological anticoagulants and activated protein C resistance in childhood stroke

Immunological and functional protein S, protein C and antithrombin III levels and anticoagulant responses to activated protein C were measured in 24 patients with stroke in childhood. No hereditary deficiencies were found. The protein S levels in healthy controls of younger age did not differ from the adult levels. For optimal screening of protein S deficiency, measurements using functional as well as immunological assays are recommended. Appropriate criteria for the diagnosis of the deficiencies must be carefully applied if unnecessary anxiety and inappropriate treatment of children are to be avoided.     

Nutritional factors and thalassaemia major

Abnormal growth is a common feature of thalassaemia major in children. In an attempt to determine whether it has a nutritional cause, 12 children aged 1 to 3 years with thalassaemia major were studied under metabolic ward conditions. Nutritional status was assessed by anthropometry and biochemistry before and after an intensive nutrition regimen. Five children had wasting or stunting on admission. As a result of the nutrition intervention, mean weight for height improved significantly. The mean height increase of 0.4 cm after one month was not significant. Plasma zinc, depressed in half the children on admission, improved, as did alpha tocopherol, while copper decreased. Plasma insulin-like growth factor-I also increased commensurate with improved growth. Fat absorption was normal in all children. Undernutrition is an important cause of associated growth disturbances in children with thalassaemia major. Malnutrition was primarily caused by inadequate nutrient intake, as indicated by the capacity to gain weight appropriately when provided with nutrition support, and by the absence of intestinal malabsorption. While long term studies are required to determine if nutritional support will prevent stunting, these results underscore its central role in preventing nutritional deficiencies and in promoting normal growth in thalassaemic children.     

MRI findings of closed head injury in children; with special reference to the effect of central shearing force]

It is considered that shearing effect as introduced by Holbourn may produce central concussion, diffuse brain swelling and diffuse axonal injury according to its grade of force. MRI was performed in 38 children who had been admitted to our hospital during the previous 1 year for the treatment of closed head injury of varying severity. In 8 out of 38 cases, abnormal high signal intensity was observed in the medial and para-medial brain parenchyma on MRI. All of these 8 cases suffered from head trauma caused by motor vehicle accidents. They included 2 cases of cerebral concussion, 1 of diffuse brain swelling, and 5 cases of diffuse axonal injury. In 2 cases of cerebral concussion, MRI (T2 weighted) revealed only localized high intensity in the corpus callosum, while CT showed normal and subarachnoid hemorrhage only at the interposium. These two children had been unconscious for periods of 20 to 30 minutes. In one case of diffuse brain swelling, MRI (T2W) showed a slightly obscure border between gray and white matter due to generally increased intensity. In 5 cases of diffuse axonal injury, most of these cases manifested lesions at the corpus callosum, deep white matter, periventricular gray matter, pons, midbrain and the cerebellum as demonstrated by high signal intensity on MRI (T2W) while CT in the acute stage showed small hemorrhage at the corpus callosum, corticomedullary junction and mid-brain and in the ventricles. Among these, two cases also demonstrated subdural hematoma and cortical contusional hemorrhage. At 3-4 weeks after injury, the area of high intensity previously demonstrated in the deep white matter and the corpus callosum on MRI (T2W) was reduced.(ABSTRACT TRUNCATED AT 250 WORDS)     

Direct demonstration of transsynaptic degeneration in the human visual system: a comparison of retrograde and anterograde changes

Transneuronal degeneration of retinal ganglion cells was directly demonstrated in a patient who had unilateral removal of the striate cortex forty years prior to necropsy. For comparison, another case is presented showing anterograde transneuronal atrophy forty years after enucleation of one eye.     

Clinical value of serum squamous cell carcinoma antigen in the management of sinonasal inverted papilloma

BACKGROUND: Although sinonasal inverted papilloma (IP) is a rare benign tumor, it has a tendency to recur and is sometimes associated with squamous cell carcinoma (SCC). Therefore, postoperative long-term follow-up of these patients is recommended. We previously reported that serum SCC antigen might be a useful tumor marker for sinonasal IP. In this study, we investigated whether serum SCC antigen level has a correlation with disease status and is useful in the early detection of recurrent disease. METHODS: Blood samples for the analysis of serum SCC antigen were taken from 28 IP patients before and after surgical treatment. RESULTS: Twenty-five (89%) of 28 cases showed evaluated serum SCC antigen levels above the upper limit. This marker level decreased in all cases after surgical resection. Four of these patients had a recurrence. None of the patients with recurrent tumor showed symptoms at the time of detection of their recurrent tumor, and recurrence was discovered from elevated levels of SCC antigen. CONCLUSIONS: Serum SCC antigen level has a correlation with disease status of IP and has a potential to serve as a useful tool for monitoring the course of disease. SCC antigen is a reliable tumor marker in the management of sinonasal IPs.     

Effects of the angiotensin-I converting enzyme inhibitor perindopril on tumor growth and angiogenesis in head and neck squamous cell carcinoma cells

Purpose Recently, it has been reported that angiotensin-I converting enzyme (ACE) inhibitors have anticancer activity. In particular, the ACE inhibitor, perindopril, significantly inhibits tumor growth and angiogenesis in hepatocellular carcinoma cells along with suppression of the VEGF level. However, the mechanisms of suppression of the VEGF level are still unclear, and there are no previous reports on this subject related to head and neck squamous cell carcinoma (HNSCC). In some previous studies, angiotensin II, which is produced from angiotensin I by ACE, directly stimulates VEGF expression.Methods In the present study, we focused upon angiotensin II, and investigated the effect of perindopril on VEGF expression, angiogenesis, and tumor development of HNSCC with in vitro and in vivo studies.Results In the in vitro cell proliferation assays, there was no significant difference between the perindopril-treated group and the control group. However, the perindoprilat-treated group showed a significant reduction in mRNA expression of VEGF and inhibited the induction activity of the VEGF promoter in comparison to the control group. Perindoprilat treatment also significantly suppressed angiotensin II production in vitro. In the in vivo studies, perindopril had a significant inhibitory effect on tumor growth, and reduced blood vessel formation surrounding the tumors.Conclusions Our findings suggest that perindopril has no direct cytotoxicity against tumor cells, but has a potential to inhibit tumor growth due to suppression of VEGF-induced angiogenesis in vivo. Angiotensin II might have an important role in carcinogenesis, and the antiangiogenic activity of perindopril is at least partly mediated by angiotensin II inhibition. The ACE inhibitor perindopril has clinical potential as a useful antitumor agent.