Saphenous vein graft for bypass of the external carotid artery to supraclinoid internal carotid artery using a modified technique: an anatomical and technical study

OBJECTIVE: To investigate the use of a saphenous vein graft for bypass of the external carotid artery (ECA) to supraclinoid internal carotid artery (ICA) when the proximal middle cerebral artery (MCA) is not suitable for a bypass procedure. MATERIAL AND METHODS: Five adult cadaver sides were used. Dissection required a frontotemporal craniotomy and a zygomatic arch osteotomy, with a hole being opened 2-3 mm lateral to the foramen rotundum extradurally. The ECA was found easily via a second incision in the cervical region. The ophthalmic segment of the ICA was exposed by removal of the anterior clinoid process intradurally. After the dura over the hole was opened, the 7-8-cm long bypass graft was passed just behind the mandibula and through the hole inside the dura to reach the ICA. The ECA was then transected proximal to the occipital artery (OA) branch and the distal side of the vein graft was anastomosed end-to-end with the ECA and end-to-side with the supraclinoid ICA. RESULTS: The mean diameter of the ECA proximal to the OA was 3.75+/-0.4 mm (range 3.35-4.15 mm) and that of the supraclinoid ICA was 3.4+/-0.5 mm (range 2.9-3.9 mm). The mean length of the venous graft was 7.5+/-0.5 cm (range 7-8 cm). CONCLUSION: When high blood flow is needed and the proximal MCA is not suitable for a bypass, the bypass described herein may be an alternative to a superficial temporal to MCA bypass as well as to extracranial carotid artery to MCA or ICA bypasses, which both need long vein grafts.     

A modified technique to bypass the maxillary artery to supraclinoid internal carotid artery by using radial artery graft: an anatomical study

OBJECTIVE: This study aims to examine the use of a radial artery graft for bypass of the maxillary artery (MA) to the supraclinoid internal carotid artery (ICA) in treating ICA occlusions. STUDY DESIGN AND SETTING: This method was carried out on five adult cadaver sides. The MA was reached 1-2 cm inferior to the crista infratemporalis, following a frontotemporal craniotomy and a zygomatic arch osteotomy. Extradurally 2-3 cm lateral to the foramen rotundum, a hole was drilled in the sphenoid bone with a 4 mm tipped drill. A radial artery graft was passed through the hole to the inside of the dura. Before giving the infraorbital artery branch, the MA was dissected from the surrounding tissue and transected. The proximal end of the graft was anastomosed end-to-end with the MA and the distal end of the graft end-to-side with the supraclinoid ICA. RESULTS: The mean calibre of the MA was 2.6 +/- 0.3 mm. The mean calibre of the proximal end of the radial artery graft was 2.5 +/- 0.25 mm and the distal end was 2.35 +/- 0.2 mm. The mean length of the radial artery graft was 4.0 +/- 0.5cm. CONCLUSION: This study suggested that the cases with ICA occlusion, which require high blood flow, may be treated as an alternative to current bypass methods requiring long vein grafts.     

Oxidatively modified fibrinogen modulates blood rheological parameters

We studied the effect of UV-oxidized fibrinogen with oxidation degrees of 10 and 20% on rheological parameters of the blood. The effect of fibrinogen with 10% oxidation degree was moderate and variable, which attests to its partial compensation with the pool of natural antioxidants. The effect of fibrinogen with 20% oxidation degree was more pronounced. It dramatically decreased deformability of erythrocytes, delayed formation of linear aggregates, accelerated formation of 3D-aggregates, enhanced the total hydrodynamic strength of aggregates, but decreased stability of the largest aggregates. It did not increase plasma viscosity, but enhanced viscosity of the blood at all shear rates. At both degrees of oxidation, suspension stability of the blood decreased, the Caisson viscosity did not change, and the difference between the values of Caisson and asymptotic viscosities markedly increased. On the whole, oxidative fibrinogen produces negative changes in blood rheological parameters, and its effect depends on the degree of oxidation.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 11, pp. 527–529, November, 2004     

Non-enzymatic glutathione reactivity and in vitro toxicity: a non-animal approach to skin sensitization.

The development of non-animal methods to predict the potential of chemicals to cause skin sensitization is of great importance. On the basis of many published studies into the underlying chemical mechanisms skin sensitization, the immunological priming which leads to the disease allergic contact dermatitis, is recognized as a reactive chemistry endpoint. Consequently, the combination of chemical assays with in vitro techniques may provide a useful surrogate to animal testing for skin sensitization. This study attempts to investigate the relationship between skin sensitization assessed in the local lymph node assay (LLNA) initially and a thiol reactivity index based on glutathione (GSH), pEC(50) thiol (EC(50) being defined as the concentration of the test substance which gives 50% depletion of free thiol under standard conditions) in combination with a measure of cytotoxicity (pIGC(50)) to Tetrahymena pyriformis (TETRATOX). The pEC(50) thiol values and the pIGC(50) values were determined for twenty-four compounds for which LLNA test data were available. Thiol reactivity was found to discriminate sensitizers from non-sensitizers according to the rule: pEC(50) thiol>-0.55 indicates that the compound will be a skin sensitizer. However, because of metabolic activation a pEC(50) thiol<-0.55 does not necessarily mean that the compound will be a non-sensitizer. Excess toxicity to T. pyriformis (i.e. the extent of toxic potency over that expected by non-polar narcosis) was determined in order to assess biological reactivity. The best discrimination based on excess toxicity in the TETRATOX assay was given by the "rule": excess toxicity>0.50 indicates that the compound will be a skin sensitizer. These approaches become more powerful when combined. When taken together, the thiol and TETRATOX assays predict the sensitization potential of 23 of the 24 compounds correctly. alpha-Hexylcinnamic aldehyde is incorrectly predicted to be a non-sensitizer, whereas LLNA results suggest it may be a weak sensitizer, this inaccuracy being rationalized in terms of its high hydrophobicity. Due to the selectivity of electro(nucleo)philic reactions some sensitizing compounds will not be identified using a single nucleophile such as thiol.     

Prevalance and risk factors for yeast colonization in adult diabetic patients

The aim of this study is to describe the associations between various host characteristics and yeast colonization; biofilm and phospholipase production in diabetic patients. The study was conducted between January 2003 and June 2003 in Abant Izzet Baysal University, Duzce, Turkey. One hundred and fourty five diabetic patients were included to the study. All oral and faecal specimens were placed on Sabourand dextrose agar with chloramphenicol and gentamicin. All isolates were identified with classic methods and carbohydrate assimilation patterns using API 20 CAUX. C. dubliniensis isolates were identified by CHROM agar Candida and chlamydospore formation according to the referral to the literature. Biofilm and phospholipase production was assessed by using previously described methods. The most common colonized species were C. albicans in oral and faecal cultures. C. dubliniensis was isolated in four oral cultures of the patients. Dental prosthesis, tooth brushing, older age, antibiotic use in the previous two weeks were found to be the significant factors for the oral yeast colonization. Younger age, smoking, shorter duration of diabetes, hospitalization in the last year and antibiotic use in the previous two weeks were found to be the significant factors for the faecal yeast colonization. Biofilm production was found to be positive in nine cases of oral and seven of faecal isolates. Phospholipase production was determined to be positive in 18 cases oral and 14 of faecal isolates. In conclusion, glycaemia control and other diabetic factors are not effective for yeast colonlizing. There was not any significant correlation between biofilm and phospholipase production and host characteristics in yeast colonization. Oral hygiene may be an effetive for decreasing the oral colonization in diabetic patients.