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Biomedical subjects

C White

Publications and source records attributed to C White.

At least 181 records · Page 10Linked to original sources
PubMed1994

Lower brain-stem origin of the median nerve N18 potential.

A patient undergoing intraoperative median nerve somatosensory evoked potential (MSEP) and brain-stem auditory evoked response (BAER) monitoring showed changes during basilar artery aneurysm clipping. There was loss of the BAER wave V, with preservation of waves I and III. Simultaneously, there also was loss of the MSEP N20 potential, with preservation of the N18, N13 and Erb's point potentials. The patient died and autopsy showed an infarct involving the whole rostro-caudal extent of the pontine tegmentum. This combination of electrophysiologic and pathologic findings may help answer questions regarding the exact generators of different MSEP potentials. In particular, it implies that medullary structures can generate the N18 potential.

Brain Stem↗
PubMed1994

A histomorphometric study on the healing of class III furcations utilizing bone labelling in beagle dogs.

The dynamics of bone turnover in the furcations of teeth treated with expanded polytetrafluoroethylene (ePTFE) membranes were evaluated using multiple fluorochrome labels in 6 male beagle dogs. Loss of attachment involving the furcation area was induced in the second, third, and fourth premolar teeth using silk ligatures. The resulting defects were treated with the use of mucoperiosteal flaps for access, debridement of the defects, and placement of ePTFE membranes covering the furcations of the second and fourth premolars (experimental teeth) while the third premolar received only debridement without membrane placement (control tooth). Five fluorochrome labels were administered intravenously at timed intervals to act as markers of the osseous response. Membranes were removed at 4 weeks and all animals were terminated at 12 weeks post-membrane placement. One side of the mandible was decalcified, sectioned at 7 microns, and stained with either hematoxylin and eosin or Gomori's tri-chrome. The opposite side provided non-decalcified tissue processed as 100 microns ground sections. Using fluorescent light and point-hit evaluation, tissue in the coronal half of each specimen was classified as either labelled bone, unlabelled bone, or resorption space. In addition, microradiographs were prepared of each ground section and specimens classified as either woven bone, old lamellar bone, or new lamellar bone. No significant differences in attachment levels, or level of junctional epithelium, were observed in decalcified sections although greater remodeling activity was noted in the experimental specimens. Comparison of ground sections revealed significant differences (P < 0.05) in all categories with both methods of evaluation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Infusional cisplatin and etoposide in the treatment of stage III-B and IV non-small cell lung cancer: a well tolerated regimen.

Twenty-eight evaluable patients were treated with an infusion of cisplatin and etoposide for advanced non-small cell lung cancer. A response was demonstrated in 43%, although only two patients had documented partial responses. The regimen was surprisingly low in toxicity, both acute and chronic, and is suitable for palliation of patients who are elderly or suffer from chronic illnesses which preclude more agressive therapy.

Adult↗
PubMed1994

Global monitoring of positive surgical outcome: a feasibility study at the Royal National Throat Nose and Ear Hospital.

We present early results of a study looking at the feasibility of positive outcome 'monitoring' after every operation at the Royal National Throat Nose and Ear Hospital. A system for quantitative 'measurement' of outcome after every operation is still light years away, and as a result audit of outcome has lagged behind audit of structure and process. Our 'monitoring' approach involves simply documenting, for every patient, whether the individual goal of the operation has or has not been achieved. Piloting this system over a 6-month period in 1993 suggests that it is feasible and useful, providing the results are used as pointers to more detailed study, rather than as endpoints in themselves.

Feasibility Studies↗
PubMed1993

Human cartilage gp-39, a major secretory product of articular chondrocytes and synovial cells, is a mammalian member of a chitinase protein family.

One of the major secreted proteins of human articular chondrocytes in monolayer or explant culture and of synovial fibroblasts is a glycoprotein with an apparent molecular weight of approximately 39,000, referred to as human cartilage glycoprotein-39 (HC gp-39). The protein was purified, and its complete cDNA sequence was determined. It contained an open reading frame coding for a 383-amino acid long peptide. Comparison of the deduced amino acid sequence with known sequences revealed that HC gp-39 contained regions displaying significant homology with a group of bacterial and fungal chitinases and a similar enzyme found in the nematode, Brugia malayi. In addition significant homologies were observed with three mammalian secretory proteins of as yet unknown function, suggesting that a related protein family exists in mammals. The human protein does not possess any glycosidic activity against chitinase substrates, arguing against any function as an endoglycosidase with specificity for N-acetylglucosamine. Analysis by Northern blotting and by reverse transcription/polymerase chain reaction showed mRNA for HC gp-39 to be present in human articular chondrocytes as well is in liver, while mRNA was undetectable in muscle tissues, lung, pancreas, mononuclear cells, or fibroblasts. Neither the protein nor mRNA for HC gp-39 was detectable in normal newborn or adult human articular cartilage obtained at surgery, while mRNA for HC gp-39 was detectable both in synovial specimens and in cartilage obtained from patients with rheumatoid arthritis. These observations suggest that the expression of HC gp-39 may be related to a response of these cells to an altered tissue environment.

Adipokines↗
PubMed1993

Structure of diaquatetrakis(mu-2,6-difluorobenzoato-kappa O:kappa O')dicopper(II).

The structure consists of centrosymmetric dimeric units, [Cu(C6H3F2COO)2(H2O)]2, formed from the bridging of pairs of copper(II) ions by carboxylate groups from four different 2,6-difluorobenzoate anions. The distorted octahedral coordination about each CuII ion consists of four carboxylate O atoms, a water molecule and a centrosymmetrically related copper ion. The Cu...Cu distance is 2.613 (1) A. The most significant feature of the crystalline structure is the water-mediated coordination of one of the carbon-bound F atoms to the copper ion through a strong C--F...H--O hydrogen bond [F...O 2.962 (4) A, F...H--O 163 degrees]. Each 2,6-difluorobenzoate aryl group is twisted considerably from its corresponding carboxyl group plane [48.9, 104.2 degrees].

Benzoates↗
PubMed1993

Evaluation of product equivalence during process optimization for manufacture of a human IgM monoclonal antibody.

We have developed a battery of tests to characterize monoclonal antibodies and assess the effect of potential manufacturing process changes. Tryptic peptide mapping, molecular weight determination by HPLC and classical light scattering, isoelectric focussing, oligosaccharide mapping by HPAE-PAD chromatography, circular dichroism spectra and differential scanning calorimetry were applied as sensitive assays of antibody structure. Biological activity was assessed by measurement of specific antigen binding activity, binding spectrum and opsonic activity. Pharmacokinetics was assessed by clearance rate studies in rats. The sensitivity of this battery of assays was demonstrated by the ability to readily detect differences between a human monoclonal antibody (IgM-2) produced by in vitro cell culture versus ascites culture. These same tests support equivalence of a second monoclonal antibody (IgM-1) produced before and after in vitro cell culture process improvements which resulted in a twofold increase in product titer.

Animals↗