Intraoperative high field magnetic resonance imaging in neurosurgery: Our initial experience with the brain suite.

We present our initial experience with the high field (1.5T) intra-operative magnetic resonance imaging, the operating room set-up, our initial cases, the difficulties we faced and how this tool affected a change in the surgical strategy intra-operatively and finally our results. 11 patients were operated on from June 1st to August 1st 2006 of which there were astrocytomas (7), pituitary adenoma (1), craniopharyngioma (1) and meningiomas (2) Localization and lesion targeting were accurate, intra-operative imaging helped to assess the resection volumes, enable corrections for brain shift, perform further tumor resection at the same sitting and help preserve eloquent cortical areas. Gliomas formed 63.6% of the tumors operated on and in 71.4% of these, our surgical strategy changed intra-operatively. Meningiomas formed 9.1% of the tumors operated and image guidance enabled a minimally invasive approach, although no change in our surgical plan was required. One pituitary adenoma and a craniopharyngioma were also operated on with good outcome.

Primary fibrosarcoma of brain.

This is a case presentation of a young patient with an intracranial space-occupying lesion following multiple episodes of generalised tonic clonic seizures for the last 20 years. Such a long latency period between the onset of fits and the discovery of an intracranial lesion is highly unusual in malignant brain tumours. This lesion was excised completely and proved to be a primary lesion of the brain - fibrosarcoma. These rare tumours of mesenchymal origin in the central nervous system are very rare.

Relative ranking of culture media based on proliferation kinetics and spontaneous chromosomal aberrations in PHA-responsive human peripheral blood lymphocytes.

Proliferation kinetics and spontaneous yield of chromosomal aberrations phytohemagglutinin (PHA)-responsive peripheral blood lymphocytes were studied from blood samples collected from 45 individuals in 4 different synthetic media. Except for a significant difference for Eagle's MEM and RPMI 1640, the other media did not show difference for the yield of chromatid or chromosome type of aberrations. Differences were however noticed in the proliferation kinetics (mitotic and proliferative rate indices) of cells among the media used. The study indicated that (i) the intrinsic properties of media which influence proliferation rate and yield of chromosomal aberrations are independent of each other as higher proportion of first division cells do not correspond with higher frequency of chromosomal aberrations, (ii) the amount of free-radical scavengers present in the medium, apart from the genetic make-up of the individuals, may contribute to the spontaneous yield of chromosomal aberrations and (iii) RPMI 1640 medium, which showed higher transformation and faster cycling rate for the lymphocytes, may be considered as medium of choice for analysing two main cytogenetic end-points, chromosomal aberrations and sister chromatid exchanges (SCEs).

Effect of storage duration on cell cycle kinetics and yield of chromosomal aberrations in PHA-responsive human peripheral blood lymphocytes.

Phytohaemagglutinin (PHA)-responsive lymphocytes from human peripheral blood samples, either irradiated or un-irradiated, showed increased frequency of first division metaphase cells (detected by fluorescence plus Giemsa (FPG) staining) as a function of duration of storage. Irradiated and subsequently stored samples showed small but significant increase for the yield of dicentrics. The yield of aberrant metaphases and deletions (excess acentrics) remained unchanged. Increasing Bromodeoxyuridine (BrdU) concentrations slowed down the cell cycle progression but did not influence the yield of aberrations including that of dicentrics.

Distribution pattern and dose-response-relationship of chromosome aberrations in human lymphocytes induced in vitro by 60Co gamma-rays and 110 kV X-rays.

Peripheral blood lymphocyte culture system was used to construct reference dose-response curves for 60Co gamma-rays and 110 kV X-ray-induced chromosome aberrations at 6 dose points ranging from 0.25 to 4.0 Gy. Qualitative and quantitative differences between these two types of radiation for the yield of induced aberrations and their distribution pattern were analysed. Experimental data of aberration yields were compared after fitting them to five different dose-response models. The yields of chromosome aberrations in particular dicentrics, gave a good fit to linear-quadratic besides linear and power models. In this model, single-track events predominated over double-track events for both the qualities of radiation used. The pattern of distribution was mainly Poisson for dicentrics but gave a conflicting result for acentrics which was in excess.