The Korean Spinal Neurosurgery Research Society expanded in terms of popularity and membership steadily over the following decade and, on December 17, 1999, it was renamed the Korean Spinal Neurosurgery Society with the approval of the Korean Neurosurgical Society. On March 18, 2008.
Barlas, et al. in 1999, reported a reduction in mortality from 18 to 0% in patients with brain abscess from the pre-CT era to the post-CT era, which they attributed to the advent of CT-guided stereotaxis 2).
It was the first human chromosome to be fully sequenced.
Identifying genes on each chromosome is an active area of genetic research, because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. Chromosome 22 contains about 693 genes.
Chromosome 22 was originally identified as the smallest chromosome. After extensive research, however, researchers concluded that chromosome 21 was smaller. The numbering of these chromosomes wasn't rearranged because of chromosome 21 being known by that designation as the chromosome that can lead to Down syndrome.
Loss of chromosome 22 and gain of 1q are the most frequent genomic aberrations in ependymomas, indicating that genes mapping to these regions are critical in their pathogenesis. Using real-time quantitative PCR, we measured relative copy numbers of 10 genes mapping to 22q12.3-q13.33 and 10 genes at 1q21-32 in a series of 47 pediatric intracranial ependymomas. Loss of one or more of the genes on 22 was detected in 81% of cases, with RAC2 and C22ORF2 at 22q12-q13.1 being deleted most frequently in 38% and 32% of ependymoma samples, respectively. Combined analysis of quantitative-PCR with methylation-specific PCR and bisulphite sequencing revealed a high rate (>60% ependymoma) of transcriptional inactivation of C22ORF2, indicating its potential importance in the development of pediatric ependymomas. Increase of relative copy numbers of at least one gene on 1q were detected in 61% of cases, with TPR at 1q25 displaying relative copy number gains in 38% of cases. Patient age was identified as a significant adverse prognostic factor, as a significantly shorter overall survival time (P = 0.0056) was observed in patients <2 years of age compared with patients who were >2 years of age. Loss of RAC2 at 22q13 or amplification of TPR at 1q25 was significantly associated with shorter overall survival in these younger patients (P = 0.0492 and P = < 0.0001, respectively). This study identifies candidate target genes within 1q and 22q that are potentially important in the pathogenesis of intracranial pediatric ependymomas 3).
Cheng et al. in 1999 reported a case of nasal dermoid sinus cyst associated with colloid cyst of third ventricle and proposed a fascinating theory of “anterior neuropore corridor defects” to explain the spectrum of these associated rare midline lesions. According to this theory, defective closure of situs neuroporicus promotes the neuroepithelium adjacent to commissural plate derivatives to form a vacuolated paraphysis growing slowly as colloid cyst of the third ventricle 4).
1999: Thieme’s classic brain atlases are digitized and incorporated in the operative planning software of neurosurgical workstations
The initial ProDisc lumbar artificial disc was developed by Thierry Marnay 5) in 1989, and was used clinically in the early 1990s. Subsequently, the second generation, ProDisc II was developed in 1999 with cobalt chrome endplates and constrained polyethylene core and approved for commercial use in Europe the same year.
Dexmedetomidine has 8 times more affinity than clonidine for α-2 receptors is bringing newer concepts in anesthesia and intensive care practice. It was approved by the Food and Drug Administration (FDA) in 1999 for use in humans for short term sedation in the intensive care unit. Initially used for sedation and analgesia in intensive care, its use has been extended to other various clinical situations as well as in regional anesthesia as a useful adjunct.