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Biomedical subjects

L Rabow

Publications and source records attributed to L Rabow.

At least 19 recordsLinked to original sources
PubMed2001

Mechanism of action of Escherichia coli formamidopyrimidine N-glycosylase: role of K155 in substrate binding and product release.

Escherichia coli formamidopyrimidine N-glycosylase (fpg) is a DNA glycosylase with an associated beta,delta-lyase activity. We have recently shown that the highly conserved lysine residue K155 is important for base recognition. Incubation of a double-stranded DNA containing an abasic site with the wild-type fpg protein generated only beta,delta-product. However, incubation of a double-stranded DNA containing an abasic site opposite a small gap with fpg protein generated predominantly beta-product. These data suggested that the induction of a double-strand break by fpg led to the destabilization of the protein-DNA covalent intermediate, causing the fpg protein to prematurely dissociate from the DNA substrate. Furthermore, when a double-stranded DNA containing an abasic site opposite an A was used as a substrate, K155A mutant fpg protein yielded a mixture of beta- and beta,delta-products. These data suggested that K155 is essential for maintaining the stability of the intermediary protein-DNA covalent complex. Pre-steady-state burst kinetics showed that mutation in K155 led to the apparent disappearance of the initial burst, suggesting that the rate of product release from K155A is much greater than the rate of chemical reaction catalyzed by the mutant enzyme. This is consistent with the idea that K155A dissociates prematurely from the covalent complex, leading to a higher turnover number observed for K155A for DNA substrate containing an AP site.

Apurinic Acid↗
PubMed1998

[Disk surgery--neurosurgery, orthopedic surgery or both?].

Bibliometric methods have been used to study the distribution of research literature on disc surgery between neurological and orthopaedic departments globally and within each of the Nordic countries. Worldwide, the total number of indexed papers was found to be almost twice as great for neurosurgical as for orthopedic institutions. Though figures for the Nordic countries were lower, they manifested the same trend, except those for Sweden where orthopaedic surgeons appear to do more research than neurosurgeons in this field. Moreover, it was found that a greater proportion of neurosurgeons than orthopaedic surgeons had published papers in journals outside their own field (29 vs 9 per cent respectively), and that 14 per cent of the neurosurgical reports had been published in orthopedic journals, but none of the orthopedic reports had been published in neurosurgical journals. Finally, scrutiny of the reference literature cited in randomly selected samples of papers from neurosurgical and orthopedic departments showed 22 per cent of the references in neurosurgical papers to be to orthopaedic journals or textbooks, but only 4 per cent of those in orthopedic papers to be to neurosurgical texts. The possible implications of these findings are discussed in the article, as are the methodological sources of error.

Humans↗
PubMed1995

Does a routine operation for intracranial aneurysm incur brain damage?

A biochemical marker of brain cell damage, the BB-isozyme of the intracellular enzyme Creatine Kinase (CK), was used to evaluate any possible injury to the brain, caused by an operation for a ruptured intracranial aneurysm (SAH). CSF-CK BB was assessed before and at intervals after operation in a series of 60 patients, aged 29-71 (mean 51 years) operated on for intracranial aneurysms, all but one after SAH. The m/f ratio was 18/42. 35 of the 60 patients were operated on acutely, i.e. within 72 hours after the SAH. CK BB was determined as CKB-activity after immunological inactivation of CKM. Normally there should be almost no detectable enzyme activity in the CSF. The pre-operative CK BB-activity was 0.01+ -0.01 mikrokatal in the patients in Hunt & Hess grade I who were operated on > 7 days after their SAH, and 0.05+ -0.04 in those operated on acutely, probably still reflecting the effects of the SAH on the brain. The mean per-operative CK BB increase was 0.11+ -0.17 for patients who had an uneventful postoperative course, compared to 0.39+ -0.49 for those showing some degree of immediate postoperative deterioration. This difference is significant at the 1% level. 52 of the 60 patients showed a rise of CK BB after operation. The mean increase for those patients operated upon in a good state and without any complication or postoperative deterioration was 0.02+ -0.03 mikrokatal, which could therefore be considered as a "normal" or acceptable elevation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Neurosurgical publications in European journals.

The number of papers published in European neurosurgical journals during the last decade (1980-90) was analysed using online databases. Thirteen journals devoted to neurosurgery were published in Europe at that time. In five of them neurosurgery appears together with other specialties. Almost 50% of all European neurosurgical journals are written in English. They published 68% of all papers by neurosurgeons appearing in the European neurosurgical journals during the last decade. Together with the American neurosurgical journals English was used in about 80% of all neurosurgical publications. Other languages used are German and French (9% each), Russian (5%), Czech or Slovak (4%), Polish (3%), Rumanian (2%). Most papers by European neurosurgeons originate from England, followed by Germany, France, Italy and Sweden. Of the East-European countries Polish neurosurgeons contributed with 782 publications, followed by Czechoslovakia (568), Hungary (501), USSR (470) and East Germany (452). The proportion of papers published in neurosurgical journals by European neurosurgeons to those in the journals devoted to other neurosciences varied from 99% in the USSR to 12% in Austria with an average of 38%. Citation analysis indicates that only a few of the journals have a large impact on neurosurgical publications, while the others have a rather limited influence.

Cross-Cultural Comparison↗
PubMed1991

Relation between sensory disturbance and outcome after retrogasserian glycerol rhizotomy.

The relation between postoperative sensory deterioration and surgical outcome in 54 patients treated by retrogasserian glycerol rhizotomy for trigeminal neuralgia was studied. The facial sensibility was assessed one day and three months postoperatively. Thresholds for perception and pain were determined quantitatively using transcutaneous electrical stimulation and clinically by light touch and pinprick tests. At a follow-up one year after surgery there was no significant difference in pain relief between patients who did show and patients who did not show sensory deterioration at the one day or three months evaluations. Nevertheless, there was a tendency for higher recurrence rate in patients with mild or no sensory disturbance.

Aged↗
PubMed1990

Percutaneous stereotactic brain tumour biopsy and cyst aspiration with a non-invasive frame.

A non-invasive Stereoadapter was used for stereotactic CT-guided percutaneous brain biopsy in 18 patients with 16 solid tumours and four cysts. The Stereoadapter was mounted on the patient's head using ear plugs and a nasion support. After the CT study, the Stereoadapter was detached. The target was simulated on a phantom base and a probe carrier attached to the Stereoadapter. For surgery, the Stereoadapter with the probe carrier was remounted to the patient's head. Local anaesthesia was mainly used. Tissue samples were aspirated with a 2 mm diameter Sedan-Nashold biopsy cannula, introduced through a twist drill hole. Conclusive histological/cytological diagnosis was obtained in 16 of the 20 lesions. The new method proved to be reliable and quick. Since the imaging study and the surgery could be separated in time and place, the biopsy procedure was less time-consuming than previous methods of stereotactic biopsy using an invasive frame.

Adolescent↗
PubMed1989

Relationship between CT attenuation changes and post-traumatic CSF-CKBB-activity after severe head injury in man.

In order to evaluate if it is practically possible to assess the volume of contused brain tissue from the CT pictures, a comparison has been carried out between the size of the cerebral contusion(s)--as estimated from the CT scans--and the post-traumatic CSF-CKBB activity, in a series of 29 patients with severe head injury. A clearance curve for the elimination of CKBB from the CSF was constructed. The relation between contusion volume and CSF-CKBB-activity was not statistically significant, while the relationships between contusion volume and outcome, and between CSF-CKBB, as estimated at 6 hours after from the clearance curve, and outcome, were.

Adolescent↗
PubMed1989

The use of chordotomy to treat pain from gynecologic cancer.

Tumor growth in the pelvis with nerve involvement causes severe pain which is notoriously resistant to pharmacological treatment. Chordotomy is a classical method for the relief of pain. This is a retrospective study of 24 chordotomy cases, operated on at the department of Neurosurgery, and independently evaluated at the department of Gynecologic Oncology. Initially 19 patients (79%) were painfree whereas 4 patients (17%) had only moderate or no relief following the operation (one not evaluable). 10 patients remained free of pain until death. There were no serious complications. Possible causes of pain relapse are analysed. We conclude that chordotomy is worth consideration when facing severe pelvic cancer pain.

Cordotomy↗
PubMed1987

Internal neurolysis or ligament division only in carpal tunnel syndrome. II. A 3 year follow-up with an evaluation of various neurophysiological parameters for diagnosis.

48 patients with clinical and neurophysiological signs of carpal tunnel syndrome were randomized to any of two operative methods: Internal neurolysis of the median nerve with a microsurgical technique, or simple division of the carpal ligament (flexor retinaculum). After a minimum follow-up period of 3 years 81% of the patients did not report any complaints at all, and all patients considered themselves improved after operation. There was no difference between the operation groups. Therefore there seems to be no justification to perform the more difficult procedure of internal microsurgical neurolysis for treatment of the carpal tunnel syndrome. A study of the neurophysiological parameters before and after restitution showed the highest sensitivity (91%) for the sensory conduction velocity, and the highest specificity for motor distal latency and sensory distal latency (83 and 75% resp.).

Adult↗
PubMed1987

CKBB-enzyme activity in serum in neonates born after vaginal delivery and cesarean section.

Creatine kinaseBB has been analysed in blood from the umbilical cord and from venous blood within 24 hours after birth in infants without any signs of perinatal asphyxia. S-CKBB activity was found to be much higher than in adults and older children. 25% of the children born after normal vaginal delivery showed very high S-CKBB activities, higher than any of the children born by elective cesarean section. There were, however, no signs of neurological disturbances to be found in any of these children with high neonatal CKBB activities at follow-up after four years.

Cesarean Section↗