Vitreous humour

Fingerprinting the Hyaluronic Acid-Protein Complex of Human Vitreous Humour, S. A. Barker, S. J. Crews, J. B. Marsters, and M. Stacey, Clin. Chim. Acta, 11 (1965) 139-145. 

The mature vitreous contains a class of mononuclear phagocytic cells called hyalocytes (Balzas and Delinger, 1984). These cells are generally embedded in the vitreous humour 20-50 /tM away from the basal lamina, forming a single layer of scattered cells. In the developing eye they are located more centrally and are capable of synthesizing the main solid constituents of the vitreous gel. 

Vitreous humour organic acids in medium chain acyl-CoA dehydrogenase deficiency. 

Because of their chemical inertness, low surface tension and antisurfactant activity polyorganosiloxane (silicone) oils have found varied applications in medicine. These have included use as an artificial lubricant for arthritic joints191, as a means of soft tissue augmentation, and as an additive in creams and oils for burn treatment. Di-methylpolysiloxane fluids have been injected as replacement for aqueous and vitreous humour in eyes. Reactive organosilicon compounds comprise a new class of potential prophylactic and therapeutic agents192. Protection against atherosclerosis... 

Antiviral Efficacy and Clinical Use. Fomivirsen (Vitravene) is injected into the vitreous humour to treat CMV infection in the eye.42 This drug is often used to treat ocular CMV infections that are resistant to more traditional agents such as ganciclovir or fos-carnet. 

Bo tiles or containers found near victim, even if em pty Exam inatio n of cloth ing if stained orifodoursaie noted Antemortem examination ofbbod or urine samples Postmortem examination oflungand brain specimen , also vitreous humour, espe daily if the body is decomposed... 

Where a body is severely decomposed, tiie actual concentration of a (hug at the time of death may be difficult to ascertain because of its decomposition by chemical or biological means. In these cases, samples of cerebrospinal fluid and vitreous humour may aid tiie analyst because these fluids do not have direct blood supphes associated with them and are therefore free from enzymes and the likelihood of microbial contamination. 

The following postmortem concentrations were reported in a fatality attributed to oral overdosage of anileridine blood 0.9 pg/ml, bile 2.4 ig/ ml, urine 11.4pg/ml, vitreous humour 0.07pg/ml diazepam was also detected (M. A. Peat and L. Kopjak, Bull. int. Ass.forens. Toxicol., 1979, 14 3), 19). 

Serum-digoxin concentrations usually increase after death average postmortem antemortem ratios varying from 1.42 for blood from the femoral vein to 1.96 for heart blood have been reported in contrast, postmortem vitreous humour concentrations were usually lower than antemortem values (T. E. Vorpahl and J. I. Coe, J. forens. Sci., 1978, 23, 329-334). 

A 44-year-old man suffering from methanol intoxication was found comatose and had a serum concentration of 5830 pg/ml on admission. The subject died 40 hours later and the following postmortem concentrations were found (pg/ml or pg/g) blood 1420, bile 1750, brain 1590, heart 930, kidney 1300, liver 1070, lung 1270, vitreous humour 1730 (N. B. Wu Chen etal., J. forens. Sci., 1985, 30, 213-216). 

A pre-column derivatisation technique using dansyl hydrazine is used for the quantitative analyses of glucose in blood or vitreous humour in cases of people suffering from hypoglycaemia and hyperglycaemia. 

Hyaluronic acid is a naturally occurring polysaccharide that is widely distributed in body tissues and intracellular fluids, including the aqueous and vitreous humour, synovial fluid, and in the ground substance that surrounds cells (1). It is a high-molecular weight substance originally developed for use as a vitreous replacement. Although 98% of the product consists of water, it is very viscoelastic. 

The determination of the heroin metabolites morphine, morphine-6-glucuronide (M6G), morphine-3-glucuronide (M3G), and 6-monoacetyhnorphine (6-MAM) in body fluids is an important application of LC-MS in the toxicology laboratory. In some cases, codeine and codeine-6-glucuronide are determined as well. Several quantitative methods have been reported. However, only a few deal with forensic toxicology, performing the analysis in urine, serum, vitreous humour [79], and autopsy whole blood [79-80]. 

The eye (Fig. 9.32) has two barrier systems a blood-aqueous barrier and a blood-vitreous barrier. The former is composed of the ciliary epithelium, the epithelium of the posterior surface of the iris, and blood vessels within the iris. Solutes and drugs enter the aqueous humour at the ciliary epithelium and at blood vessels. Many substances are transported out of the vitreous humour at the retinal surface. Solutes also leave the vitreous humour by diffusing to the aqueous humour of the posterior chamber. 

The requirement for drug screening is to have the ability to detect as wide a range of compounds as possible in as little sample (plasma/serum/whole blood, urine/vitreous humour, stomach contents/vomit or tissues) as possible at a high sensitivity but with no false positive(s). Ideally some sample should be left to permit confirmation of the results using another technique such as paper chromatography or TLC, and quantification of any poison(s) present to aid clinical interpretation of the results. 

Hyaluronic acid Hyaluronic acid iV-acetylglucosamine-glycuronic acid Synovial fluid, vitreous humour... 

V9. Varma, R., Allen, W. S., and Wardi, A. H., The arabinose content of cerebral and vitreous humour hyaluronate-peptide. J. Neurochem. 20, 241—244 (1973). VIO. Vejlens, L., Glycosaminoglycans human bone tissue. I. Pattern of compact bone in relation to age. Calcif. Tissue Res. 7,175-190 (1971). 

Hyaluronic acid Animal (synovial fluid, vitreous humour of the eye, umbilical tissue microbial (fermentation Bacillus subtflis) P-glucuronic acid and N-acetyl-P-glucosamine (GlcNAc) linked by a-(l/3) bond. [35]... 

A wide variety of specimens can be collected to assess possible drug use. These include blood (or sometimes plasma or serum ), urine, breath, saliva, sweat in living persons, or a range of other tissues from bodies at autopsy during death inveshgations. In cadavers the most common specimens, after blood and urine, are hver, bile, and vitreous humour. Muscle, brain, bone, and fat do have uses in certain types of cases when blood is unavaUable due to decomposition or following suspicion of unusual poisons. The principal applications of some specimens are summarized in Table I. 

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