Biomedical subjects

W H Kluge

Publications and source records attributed to W H Kluge.

7 recordsLinked to original sources

PubMed2002

[Blood-cerebrospinal fluid barrier function and cholinesterase activity in cerebrospinal fluid in degenerative changes of the lumbar spine].

The objective of this study was to determine whether spinal compression associated with degenerative changes of the lumbar vertebral column induces significant alteration in defined cerebrospinal fluid parameters. Serum and lumbar cerebrospinal fluid were studied in 62 patients and 47 age-matched controls. Patients were grouped according to neurologic status, duration of symptoms, and findings in magnetic resonance imaging. Statistically significant elevations in cerebrospinal fluid/serum albumin ratio, acetylcholinesterase, butyrylcholinesterase activity, and total protein concentration were observed in lumbar cerebrospinal fluid of patients. Patients with neurologic deficits did not exhibit significant differences in cerebrospinal fluid parameters compared with patients lacking neurologic signs. No significant differences were detectable between lateral and medial compression. Acute disk herniation led to practically the same biochemical changes as chronic compression. Biochemical analysis of lumbar cerebrospinal fluid offers additional diagnostic information in patients suffering from back or leg pain associated with degenerative changes of the spine. Pathological damage to meningeal and neural tissues can be demonstrated even if neurologic signs or obvious spinal compression are missing in the radiological examination. An elevated cerebrospinal fluid/serum albumin ratio reflects alteration of the blood/cerebrospinal fluid barrier status. Increased acetylcholinesterase and butyrylcholinesterase activity point to pathophysiological impairment of neural tissues or meninges.

Acetylcholinesterase↗

PubMed2002

[Subungual chondroma, a case report].

Subungual chondroma is a rare occurrence of periosteal chondroma, which mainly affects short tubular bones of the hands and feet. Transformation towards malignancy has been described in a small number of cases; however histologic diagnosis can prove to be difficult, especially with regard to well differentiated chondrosarcoma. We report the case of a 14 year old girl with a one year history of subungual chondroma of the fourth toe with good clinical response to surgical removal.

Adolescent↗

PubMed2002

Effect of bupivacaine application on cholinesterase activities, total protein- and albumin concentration in serum and cerebrospinal fluid.

The rationale of this study was to determine whether Bupivacaine used for spinal anesthesia alters the specific secretory activity of nerve cells and/or the function of the blood/cerebrospinal fluid barrier. Four groups were assessed: (1) patients undergoing spinal anesthesia using Bupivacaine for lower limb surgery, (2) spinal Bupivacaine anesthesia without subsequent surgery, (3) local facet joint infiltration using Bupivacaine, and (4) general anesthesia for lower limb surgery without Bupivacaine application. Cholinesterase activities, total protein- and albumin concentrations in serum as well as in cerebrospinal fluid were significantly decreased after surgical intervention under spinal Bupivacaine anesthesia but remained unchanged following spinal Bupivacaine application without surgery. No significant correlation was found between Bupivacaine dosage and parameter alteration. There was no influence of intrathecal Bupivacaine application on the albumin ratio cerebrospinal fluid/serum, nor was there any significant alteration of total protein- or albumin concentrations and butyrylcholinesterase activity in the serum as a result of local injection of Bupivacaine to facet joints. These serum parameters were reduced after surgery under general anesthesia. Alterations of serum- and cerebrospinal fluid parameters investigated after surgery are not related to Bupivacaine application but to effects linked to operative treatment, i.e. suppressed secretory cell activity or protein depletion owing to blood loss. We conclude that the secretory function of cholinesterase-releasing nerve cells is not affected by spinal application of Bupivacaine. The blood/cerebrospinal fluid barrier remains intact.

Aged↗

PubMed2001

Acetylcholinesterase assay for cerebrospinal fluid using bupivacaine to inhibit butyrylcholinesterase.

BACKGROUND: Most test systems for acetylcholinesterase activity (E.C.3.1.1.7.) are using toxic inhibitors (BW284c51 and iso-OMPA) to distinguish the enzyme from butyrylcholinesterase (E.C.3.1.1.8.) which occurs simultaneously in the cerebrospinal fluid. Applying Ellman's colorimetric method, we were looking for a non-toxic inhibitor to restrain butyrylcholinesterase activity. Based on results of previous in vitro studies bupivacaine emerged to be a suitable inhibitor. RESULTS: Pharmacokinetic investigations with purified cholinesterases have shown maximum inhibition of butyrylcholinesterase activity and minimal interference with acetylcholinesterase activity at bupivacaine final concentrations between 0.1 and 0.5 mmol/l. Based on detailed analysis of pharmacokinetic data we developed three equations representing enzyme inhibition at bupivacaine concentrations of 0.1, 0.2 and 0.5 mmol/l. These equations allow us to calculate the acetylcholinesterase activity in solutions containing both cholinesterases utilizing the extinction differences measured spectrophotometrically in samples with and without bupivacaine. The accuracy of the bupivacaine-inhibition test could be confirmed by investigations on solutions of both purified cholinesterases and on samples of human cerebrospinal fluid. If butyrylcholinesterase activity has to be assessed simultaneously an independent test using butyrylthiocholine iodide as substrate (final concentration 5 mmol/l) has to be conducted. CONCLUSIONS: The bupivacaine-inhibition test is a reliable method using spectrophotometrical techniques to measure acetylcholinesterase activity in cerebrospinal fluid. It avoids the use of toxic inhibitors for differentiation of acetylcholinesterase from butyrylcholinesterase in fluids containing both enzymes. Our investigations suggest that bupivacaine concentrations of 0.1, 0.2 or 0.5 mmol/l can be applied with the same effect using 1 mmol/l acetylthiocholine iodide as substrate.

Acetylcholinesterase↗

PubMed2001

Acetylcholinesterase in lumbar and ventricular cerebrospinal fluid.

BACKGROUND: Soluble acetylcholinesterase (AChE, E.C. 3.1.1.7.) is released by neurons, glial and meningeal cells into the CSF. AChE activity in cerebrospinal fluid (CSF) is altered in various disorders of the nervous system. The objects of this study are to define a reference range for CSF AChE activity in human lumbar CSF, to prove that the enzyme activity does not depend on the blood/CSF barrier function, and to provide information about AChE in ventricular CSF. In addition, drugs used in neurosurgical care have been examined for their in vitro effects on CSF AChE activity to exclude interference with the test system. METHODS: We tested the AChE activity in 64 lumbar CSF samples collected from a clinically healthy population and in 169 ventricular CSF samples obtained from 90 neurosurgical patients. AChE activity was assayed with our inhibitor-free test procedure. RESULTS: The reference range determined for lumbar CSF AChE activity is 9.2-24.4 nmol/min per ml. Lumbar CSF AChE activity does not correlate with parameters characterising the status of the blood/CSF barrier. Ventricular puncture is only justified for underlying pathology making it impossible to provide reference data for ventricular CSF. Most measurements reveal ventricular enzyme activity below 4 nmol/min per ml. CONCLUSION: The results of this study suggest the utility of lumbar CSF AChE activity as a measure of specific secretory function in enzyme releasing cells of the nervous system.

Acetylcholinesterase↗

PubMed2001

Butyrylcholinesterase in lumbar and ventricular cerebrospinal fluid.

OBJECTIVES: This study establishes reference data for human lumbar CSF butyrylcholinesterase (E.C.3.1.1.8.) activity and investigates the enzyme activity in ventricular CSF. We comment on the relationship between CSF butyrylcholinesterase activity and other laboratory parameters. SUBJECTS AND METHODS: We investigated 64 lumbar CSF samples obtained from a clinically healthy population and 169 ventricular CSF samples collected from 90 neurosurgical patients. RESULTS: The reference range we recommend for lumbar CSF butyrylcholinesterase activity is 5.4 to 17.0 nmol/min x ml. The majority of ventricular butyrylcholinesterase activities in our patient subset ranged up to 5 nmol/min x ml. CONCLUSIONS: We established the relative influence of serum and CNS components on total CSF butyrylcholinesterase activity. The CNS fraction predominates the total butyrylcholinesterase activity in normal lumbar CSF. In ventricular CSF enzyme influx from serum outweighs the CNS component.

Adolescent↗

PubMed1999

An inhibitor-free assay of acetylcholinesterase and butyrylcholinesterase in the cerebrospinal fluid.

An inhibitor-free assay for the simultaneous determination of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in the cerebrospinal fluid (CSF) is described. It is based on our finding that the individual activity ratios of BChE on both its substrates acetylthiocholine (ACh) and butyrylthiocholine (BCh) in the CSF and in the parallel serum are identical under conditions of at least 5 mmol/l substrate concentration (Q(BChE)SE = Q(BChe)CSF). Considering that AChE only reacts with ACh as substrate and occurs with negligible activities in the serum, the measured individual activity ratio of BChE in the serum (Q(BChE)SE) and the total hydrolysis rate of ACh and BCh in the CSF do allow a precise calculation of the AChE activity in the cerebrospinal fluid. The derivation of the corresponding formula is demonstrated in detail. The inhibitor-free assay was compared with procedures using cholinesterase inhibitors (BW284c51 for AChE and/or iso-OMPA for BChE). Achieving widely identical results in particular between the procedure using the AChE inhibitor and the inhibitor-free test, the latter has decisive advantages: (1) it avoids the use of highly toxic inhibitors, (2) it minimizes the test volume needed, (3) it characterizes additionally the status of the blood-CSF barrier by means of the BChE activity ratio in the CSF and in the parallel serum.

Acetylcholinesterase↗