The Correlation between Histopathology of Herniated Lumbar Intervertebral Disc and Clinical Findings.

OBJECTIVE: Prolapsed lumbar disc is one of the most frequent diseases, which is usually presented by motor and sensory deficits. Consistency of herniated disc may play a significant role in surgical treatment and postoperative improvement. The objective of this study is to assess whether the histopathological degeneration in the sample of lumbar discs operated on is correlated to clinical variables and surgical outcomes. MATERIALS AND METHODS: A randomized double-blind prospective study of lumbar disc prolapse cases over a period of 24 months was done. Forty cases were initially included in the study. All the included cases with a scheduled lumbar discectomy in the Department of Neurosurgery, King Fahd University Hospital, Al-Khobar, Saudi Arabia, during this period were examined histologically. RESULTS: Finally, 21 patients were only considered in this study due to loss of follow-up of the other 19 patients; of these 21 patients, 18 were male and 3 were female. The youngest patient was 32 years old, and the oldest was 72 years old. There is no significant correlation between the major histopathological changes of the prolapsed discs and the clinical findings of low back pain (correlation coefficient = 0.058, P < 0.8), duration of sciatica (correlation coefficient = -0.337, P < 0.1), paresthesia (correlation coefficient = 0.111, P < 0.6), motor weakness (correlation coefficient = 0.274, P < 0.2), and reflex (correlation coefficient = 0.081, P < 0.7). Meanwhile, the correlation coefficient between numbness and histopathological degeneration score (HPDS) is not defined because all reported cases were presented with numbness. CONCLUSIONS: There is no significant correlation between the histopathological changes of the prolapsed discs and some clinical findings. Moreover, the different types of prolapsed discs' histopathological changes have no impact on the outcome of the surgery. We also concluded that the disc material undergoes certain degenerative processes with age.

Development of Thin-Film Composite Membranes from Aromatic Cardo-Type Co-Polyimide for Mixed and Sour Gas Separations from Natural Gas.

The consumption of natural gas (NG) is rapidly increasing worldwide as it is becoming the second largest fuel source after coal. However, many of the world gas reserves contain high levels of subquality NG including the presence of carbon dioxide (CO2), hydrogen sulfide (H2S), nitrogen (N2), benzene/toluene/xylene (BTX) etc., in varying amounts (up to 50% v/v in some reserves), which constitute several problems. Membrane-based NG sweetening/upgrading processes emerge as among the fastest growing technologies, due to their lower capital cost, higher energy savings, greater economic viability, etc. as compared to conventional technologies. Thus, a defective-free, multilayer thin-film composite membrane is developed from 6FDA-Durene/6FDA-CARDO block co-polyimide for the separation of sour gas from NG. The membrane shows good performance as it exhibit CO2/CH4 and H2S/CH4 selectivities ranges from 8 to 10 and 15 to 19, respectively, and CO2 and H2S permeance are 122 and 220 GPU, respectively.

Boron-containing two-photon-absorbing chromophores. 3. One- and two-photon photophysical properties of p-carborane-containing fluorescent bioprobes.

Boron-containing two-photon-absorbing fluorophores have been prepared as new bifunctional molecules, potentially useful in two-photon excited microscopy (TPEM) and boron neutron capture therapy. They are based on a one-dimensional conjugated system containing a p-carborane entity at one end of the molecule and various electron-donating groups containing oxygen or nitrogen atoms at the other end. We investigated their one- and two-photon photophysical properties. They showed efficient fluorescence in an organic solvent, as well as in water for two of them, allowing microscopy on cell cultures. High two-photon absorption cross sections were determined in the 700-900 nm range. TPEM images were obtained with these new p-carborane-containing fluorophores, with laser intensities in the submilliwatt range.

Chiari type 1 malformation in an infant with type 2 Pfeiffer syndrome: further evidence of acquired pathogenesis.

There seems to be an association between type 1 Chiari malformation (CM) and some congenital craniosynostosis syndromes. Type 2 Pfeiffer syndrome is a condition associated with premature fusion of multiple cranial sutures, cloverleaf skull (kleeblatschädel deformity), prominent ptosis, thumb and first toe abnormalities, variable syndactyly, and mutated genes for type 1 or 2 fibroblast growth factor receptor. These children generally do poorly because of significant often severe neurologic and cognitive defects, and many die very young. Roughly half of all patients with Pfeiffer syndrome, and virtually all with type 2 disease, also have type 1 CM. Chiari malformation may not be congenital but acquired as a consequence of the skull deformities and other associated intracranial factors in patients with craniosynostosis. We report a term male infant with type 2 Pfeiffer syndrome, who was not noted to have any CM on initial brain imaging done at 2 months but in whom repeated imaging demonstrated clear evidence of CM by 4 months, despite reconstructive craniotomies and unilateral ventriculoperitoneal shunt insertion. Posterior fossa decompression yielded a good result. This patient provides further evidence to support the concept of acquired tonsillar herniation in patients with craniosynostosis syndromes. The etiology seems multifactorial and related to (1) the disproportionately slow growth of the skull relative to the brain, particularly in the posterior fossa, secondary to early fusion of skull sutures, in turn secondary to congenital deficiencies in fibroblast growth factor receptors; (2) impaired venous sinus drainage; (3) hydrocephalus; and (4) resultant elevations in intracranial pressure.

Boron containing two-photon absorbing chromophores. 2. Fine tuning of the one- and two-photon photophysical properties of pyrazabole based fluorescent bioprobes.

New boron containing two-photon absorbing fluorophores have been prepared. Centered on a pyrazabole central core, various conjugated systems and end groups were investigated to modulate their physicochemical properties (alkoxy, diphenylamino, and boron dipyromethene groups). One and two-photon photophysical characterizations were performed, showing efficient fluorescence in organic solvents. High two-photon absorption cross sections were determined in the 500-800 nm range. Two-photon excited microscopy images were also obtained with these new boron containing fluorescent bioprobes with laser intensities in the milliwatt range.

Cell-permeant cytoplasmic blue fluorophores optimized for in vivo two-photon microscopy with low-power excitation.

Because of the spreading of nonlinear microscopies in biology, there is a strong demand for specifically engineered probes in these applications. Herein, we report on the imaging properties in living cells and nude mice brains of recently developed water soluble blue fluorophores that show efficient diffusion through cell membranes and blood-brain barriers. They are characterized by two-photon absorption cross-sections of 100-150 Goeppert-Mayer range in the near IR and fluorescence efficiencies of up to 72% in water. They were found to stain homogeneously the cytoplasm of cultured living cells within minutes. Moreover, their diffusion times and fluorescence characteristics in the cytoplasm suggest a hydrophobic association with intracellular membranes. Their intracellular fluorescent decays were found to be almost mono-exponential, a very favorable feature for fluorescence lifetime imaging. Two photon images of living cells were obtained with a good signal to noise ratio using laser powers in the sub-milliwatt range. This allows continuous imaging without significant photobleaching for tens of minutes. In addition, these fluorophores allowed in vivo three-dimensional two-photon imaging of mice cortex vasculatures and extra vasculature structures, with no sign of toxicity.

Conjugation of a new two-photon fluorophore to poly(ethylenimine) for gene delivery imaging.

We report herein the molecular engineering of an efficient two-photon absorbing (TPA) chromophore based on a donor-donor bis-stilbenyl entity to allow conjugation with biologically relevant molecules. The dye has been functionalized using an isothiocyanate moiety to conjugate it with the amine functions of poly(ethylenimine) (PEI), which is a cationic polymer commonly used for nonviral gene delivery. Upon conjugation, the basic architecture and photophysical properties of the active TPA chromophore remain unchanged. At the usual N/P ratio (ratio of the PEI positive charges to the DNA negative charges) of 10 used for transfection, the transfection efficiency and cytotoxicity of the labeled PEI/DNA complexes were found to be comparable to those of the unlabeled PEI/DNA complexes. Moreover, when used in combination with unlabeled PEI (at a ratio of 1 labeled PEI to 3 unlabeled PEI), the labeled PEI does not affect the size of the complexes with DNA. The labeled PEI was successfully used in two-photon fluorescence correlation spectroscopy measurements, showing that at N/P = 10 most PEI molecules are free and the diffusion coefficient of the complexes is consistent with the 360 nm size measured by quasielastic light scattering. Finally, two-photon images of the labeled PEI/DNA complexes confirmed that the complexes enter into the cytoplasm of HeLa cells by endocytosis and hardly escape from the endosomes. As a consequence, the functionalized TPA chromophore appears to be an adequate tool to label the numerous polyamines used in nonviral gene delivery and characterize their complexes with DNA in two-photon applications.

Synthesis and characterization of water-soluble two-photon excited blue fluorescent chromophores for bioimaging.

We report here the synthesis and characterization of a new type of non-ionic blue fluorescent water-soluble chromophores specifically designed for two-photon absorption microscopy. The water solubility is induced by introduction of short oligo(ethylene glycol) monomethyl ether moieties. This work has led to low molecular weight dyes with efficient two-photon absorption cross sections and high fluorescence quantum yield in organic solvents as well as in aqueous solutions.