Glucose-1-phosphatase (AgpE) from Enterobacter cloacae displays enhanced phytase activity

Using a screening procedure developed for detection of phytate hydrolysing enzymes, the gene agpE encoding glucose-1-phosphatase was cloned from an Enterobacter cloacae VKPM B2254 plasmid library. Sequence analysis revealed 78% identity on nucleotide and 79% identity on peptide level to Escherichia coli glucose-1-phosphatase characterising the respective gene product as a representative of acid histidine phosphatases harbouring the RH(G/N)RXRP motif. The purified recombinant protein displayed maximum specific activity of 196 U mg(-1) protein against glucose-1-phosphate but was also active against other sugar phosphates and p-nitrophenyl phosphate. High-performance ion chromatography of hydrolysis products revealed that AgpE can act as a 3-phytase but is only able to cleave off the third phosphate group from the myo-inositol sugar ring. Based on sequence comparison and catalytic behaviour against phytate, we propose to classify bacterial acid histidine phosphatases/phytases in the three following subclasses: (1) AppA-related phytases, (2) PhyK-related phytases and (3) Agp-related phytases. A distinguished activity of 32 U mg(-1) of protein towards myo-inositol-hexa-phosphate, which is two times higher than that of E. coli Agp, suggests that possibly functional differences in terms of phytase activity between Agp- and AppA-like acid histidine phosphatases are fluent.

[Effect of aprotinin on fibrosis of nerve sutures]

Although fibrin-glue has been used in many areas of surgery, it has not become fully established in nerve coaptation. Initially, significant advantages were expected; however, as the fibrin clot dissolved prematurely and gapping occurred, antifibrinolytic substances were added to the glue. Following this procedure, fibroses occurred frequently, which remains a problem. In this study, the influence of aprotinin's fibrosis-inducing effect was investigated. Aprotinin demonstrated no additional fibrosis-promoting effect.

[Choice of thrombin concentration of common fibrin glue systems for nerve anastomosis]

Although fibrin glue has been used in several areas of surgery with increasing success, it has not become fully established in nerve coaptation. Initially, significant advantages were expected, however, as the fibrin clot dissolved prematurely, gapping occurred and antifibrinolytic substances had to be added to the glue. Following this procedure, fibrosis occurred frequently. This remains a problem. Therefore, the dosage dependent fibrosis-inducing effect of thrombin was investigated in an animal experimental study. Thrombin demonstrates a fibrosis-promoting effect and we therefore recommend 1-1.5 NIH thrombin/ml glue, as lower concentrations increase the clotting time.

[Legal evaluation of intervertebral disk surgery including post-discotomy syndrome]

Although lumbar disc surgery (discectomy) definitely improves the overall situation of the patient in most cases, it does create problems of a hitherto absent kund in about 6% of the patients. Expertising of uncomplicated cases should not be too difficult. However, modulated by individual disposition, a syndrome may develop known as "failed back surgery syndrome" caused by intersegmental loosening, crumbling or fusing and scarification. The pain it causes is decisive for its assessment, not so much any motor or other neurological deficits. In mild cases the loss in capacity for gainful employment may be assessed at between 20% to at the most 30%, but the severely handicapped are unable to cope with their daily life without assistance, their incapacitation amounting to as much as 100%. If the patient concerned is on a job that places stress on this spine, he may be unfit for work even if the affliction is relatively mild.

[Forensic evaluation of intervertebral disk operations including the post-discotomy syndrome]

Invertebral disk operations generally lead to a significant improvement of the general condition of the patient. Nevertheless, for a considerable number of patients operated on, they can also create problems, which were not present in this form beforehand. The expert practice of assessing relatively uncomplicated procedures will be described. Generally, disability of up to 30% is considered normal. Depending on individual disposition a series of symptoms can develop due to intersegmental relaxation, adhering and formation of scar tissue, which has become known as postdiscectomy or postdiscotomy syndrome. Decisive in the assessment of this is the pain more than motor or other neurological disorders. In mild cases disability of 20% to 30% maximum is evident; patients seriously affected are no longer capable of living independently, disability can reach up to 100%. Under certain circumstances disability must be assumed even in mild cases in employment which places a strain on the vertebral column.

[Modifying regeneration success of glued nerve anastomosis by local corticoid administration]

Although the fibrin adhesion is being used in many areas of surgery with increasing success, it has, however, not become fully established in nerve anastomosis. At the beginning fibrin clots dissolved prematurely and dehiscences ensued. Antifibrinolytic substances had to be added to the adhesive to stabilize the clot. As a result fibroses occurred frequently, which up to now encumber nerve adhesive. The conventional suture technique is still not convincing also. Because reports showed a beneficial influence on conventional nerve sutures, the object of this study was a comparison between conventional suture technique and nerve anastomosis by fibrin adhesives with and without additive of corticosteroids. Electrophysiological methods were used, because regeneration is clinically determinating. The results do not recommend the use of local corticosteroids in nerve anastomoses fixed by fibrin adhesive.

[Electrophysiologic comparison between sutured and glued nerve anastomoses]

Fibrinadhesires are successfully used in many areas of surgery, but they have not been generally adopted for the construction of neural anastomoses, even though the conventional suturing technique is also not completely satisfactory. In the early phase of fibrinotherapy, dehiscence occurred. The addition of antifibrinolytics has admittedly led to stabilization of the clots, but since the introduction of this procedure fibrosis has been observed with increasing frequency. This can cause even initially successful anastomoses to fail later. The objective of the work described in the present paper was to compare the conventional suturing technique and fibrinotherapy for the fixation of anastomoses. Electrophysiological methods of measurement were used, as it is ultimately the degree of reinnervation achieved that is of decisive importance. No significant difference was noted when an epineural technique was used.

[The effect of fibrin gluing and its important components on fibrosis of nerve anastomoses]

The fibrinous adhesion, although generally adopted and more and more successfully applied in many sectors of surgery, is not yet fully established in the anastomosis of separated nerves. Initially, the adhesion was expected to offer some essential advantages in this domain, especially in the prevention of suture granulomas. However, the blood clots dissolved too early, and this resulted in the formation of dehiscences. So antifibrinolytic substances had to be added to the adhesive, and this led to a frequent appearance of fibroses. The adhesion of nerves is still hampered by this fact. Now we have examined the fibrosis-inducing effect of different factors of the adhesive system. We found that aprotinin and the fibrin clot as an obstacle to supply had no additional fibrotic effect, whereas thrombin, factor XIII and fibronectin promoted the formation of fibroses.

The influence of fibronectin on the fibrosing of a nerve anastomosis in the rat

Although the fibrin adhesion enjoys increasing success in many areas of surgery, it has not, however, become fully established in nerve anastomosis. It was in this area particularly that significant advantages were expected, especially by the avoidance of suture granulomas. As the fibrin clot dissolved prematurely, however, and dehiscences ensued, antifibrinolytic substances had to be added to the adhesive. Fibroses occurred frequently as a result, which to date encumber nerve adhesive. We examined fibronectin for its fibrosis-inducing effect, comparing both presently available fibrin adhesive systems, because one contained up to 5 times more fibronectin per milliliter than the other. On the basis of a test grouping using 100 and 1000 KIU aprotinin/ml, we were able to establish that fibronectin in fibrin adhesives possesses a fibrosis-promoting effect.

[Is there a preference among fibrin glues for nerve anastomosis?]

Although fibrin glues have been successful in many areas of surgery, they have not become fully established in nerve anastomosis, even in ENT surgery, an area where significant advantages were expected. As the fibrin clot dissolves prematurely, and dehiscences follow, antifibrinolytic substances must be added to the adhesive. Fibrosis often complicates the use of nerve adhesives. We examined both adhesive systems for their ability to induce fibrosis and their regenerative success rate. Using 1000 KIU aprotinin and 4 IU thrombin there was no significant difference on the effect of both commercially available fibrin adhesives on the collagen content of a nerve anastomosis or on the cumulative action potential in the rat. The proportion of connective tissue was about 33%. Regeneration was undoubtedly recorded.

[State of the art of nerve fibrin adhesion]

Although in use for over 15 years, commercially available fibrin adhesives are still regarded with scepticism when they are used for nerve anastomosing. We therefore studied the fibrosing potential of the two presently available fibrin adhesives by determining the amount of connective tissue in the anastomoses using light microscopy. In addition, regeneration was examined by electrophysiology. No significant differences were detected when 1000 KIE aprotinin and 3 IU thrombin were used. The amount of connective tissue was 33%, and regeneration was proven beyond doubt.

[Do fibrin glue sleeves produce fibrosis in transplanted nerves?]

Although fibrin adhesion is being used in many areas of surgery with increasing success, it has not, however, become fully established in nerve anastomosis. It was in this area particularly that significant advantages were expected. As the fibrin clot dissolved prematurely, however, and dehiscences ensued, antifibrinolytic substances had to be added to the adhesive. Fibroses occurred frequently as a result, which to date hamper its use as a nerve adhesive. We examined various factors of the adhesive system for their fibrosis-inducing effect. We were able to confirm that no additional fibrosis-promoting effect originates from the fibrin clot as a supply barrier.

The influence of factor XIII on the fibrosing of a nerve anastomosis in the rat

Although the fibrin adhesion enjoys increasing success in many areas of surgery, it has not become fully established in nerve anastomosis. It was in this area particularly that significant advantages were expected. As the fibrin clot dissolved prematurely, however, and dehiscences ensued, antifibrinolytic substances had to be added to the adhesive. Fibroses occurred frequently as a result, which to date encumber nerve adhesive. We examined Faktor XIII for his fibrosis-inducing effect because both presently available fibrin adhesives contain unphysiologically high concentrations of it. We were able to establish that Factor XIII possesses a fibrosis-promoting effect.

Problems of fibrin adhesion of the nerves

Although the fibrin adhesion enjoys increasing success in many areas of surgery, it has not, however, become fully established in nerve anastomosis. It was in this area particularly that significant advantages were expected. As the fibrin clot dissolved prematurely, however, and dehiscences ensued, antifibrinolytic substances had to be added to the adhesive. Fibroses occurred frequently as a result, which to date encumber nerve adhesive. We examined various factors of the adhesive system for their fibrosis-inducing effect. We were able to establish that no additional fibrosis-promoting effect emanated from aprotinin and the fibrin clot as a supply barrier, whereas thrombin, Factor XIII and fibronectin possess a fibrosis-promoting effect.

Cavernous hemangiomas in children

Cavernous angiomas are histologically benign hamartomas, showing no potential for metastasis. Clinically, patients present with convulsions, hemorrhage, or signs of mass effect. Although many cases exhibit ossification on X-ray, the main means of diagnosis is computed tomography. This, in turn, has led to earlier diagnoses being made in much younger patients. Early diagnosis is a matter of urgency as patients are otherwise exposed to the continuing threat of rupture. As cavernous angiomas are operable, the prognosis is usually good.

Orbital cavernous hemangiomas

Cavernous hemangiomas are the most frequently found primary tumors in the orbital region. They normally appear in adults. Diagnostic features in the majority of cases include protrusio bulbi and orbital enlargement. B-Scan and computed tomography/MRI are the prime diagnostic aids. We recommend surgical removal of these tumors, at least in cases with marked orbital protrusion or significant optic nerve compression. The prognosis is usually good.