Haematoma after cochlear implantation: management of a minor complication

CONCLUSIONS

The dimensions of the implant receiver and the material used have influenced the surgical approach leading to a reduction in complications. Ultrasonography of the haematoma is useful in the evaluation of dimensions, entity of fluid component and therapeutic options.

OBJECTIVE

Haematoma arising in the receiver area is considered a minor complication, nevertheless it can be complicated by infection and/or flap necrosis or fibrosis leading to difficulties in magnetic adherence of the receiver and rarely to explantation of the receiver. The objective of the study was to evaluate the clinical outcome of postoperative haematoma arising after cochlear implant surgery.

PATIENTS AND METHODS

This was a retrospective case series of 22 cochlear implant patients who developed post-implant haematoma over the receiver area. Haematoma extension and fluid collection were analysed via ultrasonography, implant type and predisposing factors such as trauma, coagulation disorders and type of skin incision.

RESULTS

Patients were divided into four groups on the basis of the main predisposing factor: coagulation disorders (n=7), trauma (n=3), revision surgery (n=6) and haematoma of unknown origin (n=6). The main factors correlated to haematoma onset were coagulation disorder, type of skin incision and flap revision. In all, 21 subjects had complete recovery and the speech perception performance was not compromised over time, while 1 subject (0.3%) with an extensive haematoma due to a pharmacologically induced coagulation disorder required explantation of the device.

[Abdominal pain in childhood: multidisciplinary approach. A clinical case]

The Authors describe a case of mature cystic teratoma found in a little girl 9 + 8/12 years old and removed in laparoscopic way. Various specialists' contribution shows up for the resolution of the case.

[Renal transplant rejection. Role of color Doppler sonography and comparative evaluation of fluorometric and bioptic results]

BACKGROUND

Aim of this work is to evaluate the morphological changes of the waveforms found in the parenchyma of the renal transplant rejection, establishing the prognostic significance.

METHODS

46 patients with symptomatic renal allograft underwent color Doppler ultrasound examination. The ultrasound characteristics were evaluated. The Resistive Index (RI), the morphological waveforms (divided into two groups: group A with regular waveforms, group B with irregular waveforms). Color Doppler pattern (R.I. and waveforms) were compared to histological and cytological specimens and to mean values of creatinine before and after therapy.

RESULTS

In group A, the creatinine values varied between the start of rejection symptoms and after some days, giving a significant statistic result. Group B didn't show any important variations. The RI mean value was higher in group B. Significant results concerning correlation between Doppler parameters and histological specimens were not observed.

CONCLUSIONS

The conclusion is drawn that in renal transplant rejection it is important to keep in mind also the variation of the waveforms to establish the clinical prognosis.

Redox perturbations in cysteamine-stressed astroglia: implications for inclusion formation and gliosis in the aging brain

The aminothiol compound, cysteamine (CSH), induces astrocyte hypertrophy (gliosis) and the appearance of autofluorescent, peroxidase-positive cytoplasmic granules in these cells akin to changes that occur spontaneously in astroglia of the aging periventricular brain. Paradoxically, CSH damages astroglial mitochondria (granule precursors) while protecting these cells from subsequent H2O2 and mechanoenzymatic stress. In this study, in vitro CSH administration significantly increased manganese superoxide dismutase (MnSOD) activity in cultured astroglia. Immunoblot and Northern analyses indicated that MnSOD protein and mRNA levels were increased in cultured astrocytes after 3-6 days of CSH treatment. Systemic administration of CSH also significantly augmented MnSOD activity in the intact diencephalon. CSH caused a pronounced (6-fold), but transient, increase in the level of reduced glutathione (GSH) in cultured astrocytes. In contrast, catalase and glutathione reductase (GR) activities were suppressed, whereas copper-zinc superoxide dismutase (CuZnSOD) activity remained unchanged both in cultured astroglia and in the intact diencephalon following CSH treatment. Glutathione peroxidase (GP) activity was increased after 3 and 48 h of CSH treatment and then declined below control levels in cultured astrocytes. CSH inhibited the formation of thiobarbituric acid-reactive products (TBAR) in whole astrocyte monolayers, although it promoted TBAR formation in suspensions of isolated astroglial mitochondria. CSH-related oxidative stress may accelerate aging-related changes in astroglial mitochondria while conferring cytoprotection to these cells by stimulating the upregulation of various heat shock proteins and MnSOD. These cytoprotective responses may facilitate astrocyte survival and the development of reactive gliosis in the face of concomitant neuronal degeneration. CSH-treated astrocytes may serve as a model for the (dys)regulation of neuroglial MnSOD and other antioxidant enzymes in the aging and degenerating nervous system.

Absence of mutations in superoxide dismutase and catalase genes in patients with Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is an adult-onset, neurodegenerative disorder characterized by a selective loss of the dopaminergic cells of the substantia nigra and by progressive motor decline. Studies have shown aberrant oxidative stress metabolism within the substantia nigra and other dopaminergic regions of the brain in patients with PD.

OBJECTIVE

To screen the genes of three free radical detoxifying enzymes--copper/zinc superoxide dismutase, manganese superoxide dismutase, and catalase--for mutations in patients with PD.

PATIENTS AND METHODS

A total of 107 unrelated patients with PD from two PD populations (familial and sporadic) were screened for mutations in the genes of copper/zinc superoxide dismutase, manganese superoxide dismutase, and catalase by single-strand conformation analysis. The diagnosis of PD was based on the clinical observations of resting tremor, rigidity, and bradykinesia.

RESULTS

No mutations were identified. However, we did identify an amino acid substitution (glycine to aspartic acid) in exon 9 of the catalase gene in one patient; decreased red blood cell catalase activity was observed in this patient.

CONCLUSION

Parkinson's disease is not caused by mutations in the genes of these three detoxifying enzymes. The exon 9 variant in the catalase gene in the one family with PD is most likely a silent mutation and not the genetic cause of PD in this family.

A cellular stress model for the sequestration of redox-active glial iron in the aging and degenerating nervous system

The mechanisms responsible for the accumulation of redox-active brain iron in normal senescence and in Parkinson's disease remain poorly understood. The aminothiol compound cysteamine (CSH) induces the appearance of autofluorescent, iron-rich cytoplasmic granules in cultured astroglia that are identical to glial inclusions that progressively accumulate in the aging periventricular brain. Both in situ and in culture, these glial inclusions appear to arise in the context of a generalized cellular stress (heat shock) response. Several laboratories have previously concluded that porphyrins and heme ferrous iron are responsible, respectively, for redorange autofluorescence and nonenzymatic peroxidase activity in the glial inclusions. In the present study we found that, contrary to hypothesis, CSH suppresses the incorporation of the heme precursors delta-amino[14C]-levulinic acid and [14C]glycine into astroglial porphyrin and heme in primary culture. Similar results were obtained when the cells were preloaded with radiolabeled heme precursors for 24 h before CSH treatment, suggesting that the latter directly inhibits porphyrin-heme biosynthesis rather than limiting precursor uptake by these cells. We also demonstrated that CSH exposure results in the sequestration of iron-59 by astroglial mitochondria (granule precursors). The results of this study suggest that stress-related trapping of nonheme iron by astroglial mitochondria may be an important mechanism underlying the pathological accumulation of redox-active iron in the basal ganglia of subjects with Parkinson's disease. CSH-treated astrocytes provide a useful model to investigate the role of stress-related dysregulation of neuroglial iron metabolism in the aging and degenerating nervous system.

[Metabolic and water-electrolyte changes as postoperative complications in aneurysms of the anterior communicating artery]

A study was performed on hydroelectrolytic changes in neurosurgical patients operated for clipping anterior communicating artery aneurysm. The patients were observed during a seven day period in ICU, between the preoperative day and the sixth post-operative day. No statistically significant changes were observed, except for hyponatriemia on the day of surgery. The etiology of this phenomenon is not clear: it could be a change of ADH or "cerebral salt wasting syndrome". A wider number of patients and repeated haematological tests are necessary.

Purification and characterization of leukotriene A4 epoxide hydrolase from dog lung

Leukotriene A4 epoxide hydrolase from dog lung, a soluble enzyme catalyzing the hydrolysis of leukotriene A4 (LTA4) to leukotriene B4 (LTB4) was partially purified by anion exchange HPLC. The enzymatic reaction obeys Michaelis- Menten kinetics. The apparent Km ranged between 15 and 25 microM and the enzyme exhibited an optimum activity at pH 7.8. An improved assay for the epoxide hydrolase has been developed using bovine serum albumin and EDTA to increase the conversion of LTA4 to LTB4. This method was used to produce 700 mg of LTB4 from LTA4 methyl ester. The partial by purified enzyme was found to be uncompetitively inhibited by divalent cations. Ca+2, Mn+2, Fe+2, Zn+2 and Cu+2 were found to have inhibitor constants (Ki) of 89 mM, 3.4 mM, 1.1 mM, 0.57 mM, and 28 microM respectively Eicosapentaenoic acid was shown to be a competitive inhibitor of this enzyme with a Ki of 200 microM. From these inhibition studies, it can be theorized that the epoxide hydrolase has at least one hydrophobic and one hydrophilic binding site.

Purification and preliminary characterization of 2-monoacylglycerol acyltransferase from rat intestinal villus cells

We have purified the monoacylglycerol acyltransferase from rat small intestinal mucosa to homogeneity by a combination of hydrophobic absorption, guanidine dissociation, and gel filtration. The purified enzyme gives a single band of 37 000 daltons on sodium dodecyl sulphate--polyacrylamide gel electrophoresis. The enzyme has a specific activity of about 5900 nmol/mg per hour and represents 0.12% of total cell protein, corresponding to about a 600-fold purification. The enzyme does not acylate diacylglycerols to triacylglycerols, which is consistent with the separate physical existence of the mono- and di-acylglycerol acyltransferases. The enzyme acylates the 2-monoacylglycerols to yield an essentially racemic mixture of diacylglycerols. It does not acylate glycerol-3-phosphate.

Rapid isolation of a triacylglycerol synthetase complex from rat intestinal mucosa

A triacylglycerol synthetase complex made up of acyl-CoA synthetase, acyl-CoA:monoacylglycerol acyltransferase, and acyl-CoA:diacylglycerol acyltransferase has been solubilized by sodium taurocholate and isolated by chromatography on phenyl-Sepharose. For this purpose microsomes of the villus cells of rat intestinal mucosa were dissolved in 2% sodium taurocholate prepared in 1 M (NH4)2SO4 and 25 mM Tris-HCl (pH 8.5) (buffer A). After dialysis against buffer A, the sample was loaded on a phenyl-Sepharose column and the enzyme complex was eluted with 25 mM Tris-HCl (pH 8.5) (buffer B). The enzymatically active fractions were pooled and rechromatographed on a Bio-Gel A-0.5m column equilibrated with buffer B and 150 mM NaCl. The recovered triacylglycerol synthetase complex accounted for over 75% of the original enzyme activity and represented a 145-fold purification from villus cells and a 10-fold purification from microsomes. It exhibited maximal activity at pH 8.0-9.0. On the basis of Bio-Gel A-0.5m chromatography the three enzymic activities appeared as a single fraction in the molecular weight range of 350 000-375 000. The complex migrated as a single peak on high performance liquid chromatography on an ion-exchange column using a NaCl gradient. The ratio of the activities of the three enzymes remained constant during the purification. The purified enzyme complex lost about 50% of its diacylglycerol acyltransferase activity on storage for 2 weeks at -20 degrees C in presence of phenylmethylsulfonyl fluoride.

Quantitation of natural triacylglycerols by reversed-phase liquid chromatography with direct liquid inlet mass spectrometry

Using acetonitrile and propionitrile as eluting solvents and reagent gases the yields of both quasi-molecular and fragment ions were found to vary with the molecular weight, degree of unsaturation and positional distribution of the fatty acids in the triacylglycerol molecule, and appropriate calibration factors were necessary for accurate quantitation. In the absence of pure structural isomers and mixed acid standards, preliminary calibration factors have been determined for total ion and specific ion current responses by comparing the peak area ratios obtained by liquid chromatography-mass spectrometry with the proportions of the molecular species known to be present in randomized oils and in natural oils of known chemical composition. Although the derived factors include both chromatographic and mass spectrometric effects and are obtained with a gradient of reagent gases, they appear to be generally applicable. It was shown that positional isomers affected the yield of the (MH-RCOOH)+ ions over a 1-3-fold range of intensities, while the nature of the fatty acid affected it over a range of 1.25-fold. After suitable calibration of the relative ion responses it was possible to determine the identities and amounts of the individual molecular species in natural fats and oils.

Studies on the substrate specificity of purified human milk bile salt-activated lipase

The fatty acid specificity of the bile salt-activated lipase purified from human milk was studied using C12 to C54 (total acyl carbon) saturated and the C54 unsaturated triacylglycerols. Kinetic studies indicated that the short chain triacylglycerols were hydrolyzed more readily than the long chain triacylglycerols, and that the long chain unsaturated triacylglycerols were attacked more readily than the long chain saturated triacylglycerols. This fatty acid specificity was also apparent intramolecularly, both short chain and unsaturated fatty acids being released at higher rates than the saturated long chain acids. The enzyme possessed neither positional specificity nor stereospecificity as indicated by the nearly simultaneous appearance of the sn-1,2-, sn-2,3-, and sn-1,3-dioleoylglycerols from trioleoylglycerol. The hydrolyses of these three ester bonds were approximately at their anticipated chemical reactivities. Synthetic rac-1-monooleoylglycerols were hydrolyzed about 2 times faster than the sn-2-monooleoylglycerols. It is concluded that the bile salt-activated lipase may possess a special potential for a rapid release of short chain and polyunsaturated fatty acids from dietary triacylglycerols in the intestinal lumen of infants.

Studies on the substrate specificity of purified human milk lipoprotein lipase

The fatty acid specificity of purified human milk lipoprotein lipase was studied using the C18 to C54 (total acyl carbon number) saturated and the C54 mono-, di- and triunsaturated monoacid triacylglycerols. Kinetic determinations indicated that the medium-chain triacylglycerols were better substrates than long- or very short-chain saturated triacylglycerols. The unsaturated triacylglycerols were hydrolyzed at rates comparable to that of tricaprylin with triolein having the highest rate of hydrolysis of the unsaturated species tested. The enzyme attacked the primary ester bond much more readily than the secondary ester bond. The purified human milk lipoprotein lipase showed a preferential stereospecific lipolysis of the sn-1-position of the triacylglycerol molecule.

Modulation of acylglycerol synthetase activities of rat intestinal mucosa by homogenization and sonication

Diacylglycerol and triacylglycerol synthesis was compared in intact villus cells and in their homogenates and sonicates using 2-monoacylglycerols and free fatty acids as substrates along with appropriate cofactors. It was found that simple pestle homogenization of cells led to an apparent loss of 80-90% in the triacylglycerol and 40-fold increase in the diacylglycerol synthetase activity. Sonication of the homogenate resulted in reestablishing the normal activity of cellular triacylglycerol synthesis (12 +/- 1 nmol . mg protein-1 . h-1) but the diacylglycerol biosynthesis further increased (to a maximum of 70 +/- 5 nmol . mg protein-1 . h-1). Preincubation with trypsin and postincubation treatment with pancreatic lipase indicated that different enzymes are involved in diacylglycerol and triacylglycerol biosynthesis from 2-monoacylglycerols and that these enzymes become segregated during homogenization. It is concluded that a triacylglycerol synthetase system utilizing 2-monoacylglycerols can be reassembled upon sonication.