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Biomedical subjects

M Severin

Publications and source records attributed to M Severin.

At least 37 records · Page 2Linked to original sources
PubMed1990

Recurrent Salzmann's corneal degeneration.

Three keratoplasties were carried out on two patients because of nodular degeneration of the cornea. Progress after keratoplasty could be followed up in one eye for 17 months and in the other two eyes, for 2.5 and 9 years, respectively. The implant with the short follow-up of only 17 months remained glass-clear; nothing abnormal was discovered during the checkups. In the case of the other patient in whom a longer follow-up period was possible, the following findings were evident: (1) a remarkably late epithelial immune response in one eye (after 18 months) with subsequent incomplete reepithelisation and formation of fine, superficial, cloudy opacity (observation period 2.5 years); (2) formation of dense but flat, superficial areas of opacity in the cornea of the other eye (observation period 9 years). These areas may be regarded as a precursor of Salzmann's corneal degeneration. No difference could be found between the histological findings in the explants and those in a degenerative pannus or an older scar caused by inflammation of the Bowman membrane.

Aged↗
PubMed1989

Validation of a quantitative procedure for the extraction of sterols from edible oils using radiolabelled compounds.

The work described in this paper is integrated in an analytical programme organised by the Community Bureau of Reference with the aim of developing reference materials certified for sterol content. Preliminary inter-comparison of methods showed that the level of agreement of the results was insufficient for certification purposes. Errors could occur in the different steps before the final determination by gas-liquid chromatography. It was, therefore, decided to validate a quantitative procedure for the isolation of sterols. A well defined saponification-extraction method was tested using labelled sterols ([3H]cholesterol and [3H]cholesteryl oleate) and radiochemical measurements. The study has shown that total cholesterol recovery reached 100.5 +/- 1.4%, that cholesteryl ester was saponified quantitatively and that there were no appreciable amounts of degradation products. The procedure has been used as the basis for the certification of three reference materials and it has been shown that the saponification and extraction procedure leads to the quantitative recovery of sterols regardless of the nature of the fatty material tested.

Cholesterol↗
PubMed1989

[Endothelial precipitates and cytomegalovirus infection].

In patients with the typical features of intraocular cytomegalovirus infection endothelial precipitates were identified that had a characteristic morphology, which included subtle, non-pigmented linear deposits with reticular arrangement that can spread diffusely over the corneal endothelium without preference for the inferior quadrants. The appearance of these precipitates was comparable to heterocromic cyclitis. Specular microscopy identified lymphocytes and macrophages on the endothelial layer. The present observations are based on five case reports of necrotizing retinitis, typical for intraocular cytomegalovirus infection, in connection with the atypical endothelial precipitates. In four of the five patients reported, HIV-infection was confirmed. In one patient with serologically confirmed cytomegalovirus infection (however without HIV-infection), a diagnostic work-up of the aqueous humor was carried out. Local production of specific antibodies against cytomegalovirus was identified in the aqueous humor. Topical treatment with antiviral and/or steroidal drugs was unsuccessful. The antiviral drug gancyclovir was applied systemically in two patients, but there was no impact on the corneal precipitates described. No intravitreal therapy was given. If these endothelial changes can be regarded as pathognomonic for cytomegalovirus infection, thorough slit lamp examination may be important for diagnosis of the presence of or the reactivation of cytomegalovirus infection in the eye. So far, no correlation has been found between the time course of corneal/endothelial precipitation and necrotizing retinitis.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Endothelial alterations in AIDS with cytomegalovirus infection.

We report on a patient in whom a cytomegalovirus infection occurred in connection with AIDS. Together with the alterations of the fundus typical for cytomegalovirus retinitis, reticular deposits were observed on the corneal endothelium. Specular microscopy showed occasional endothelial cells with edema, as well as small, dark, round, mobile structures (probably lymphocytes) and large, bright, spindle-shaped, immobile structures (probably macrophages) located behind the endothelium. Despite treatment with corticosteroids and acyclovir, an increase in the extent of the findings was observed. The deposits are interpreted as a reaction of the endothelium to the cytomegalovirus infection.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Diffuse epithelial ingrowth after perforating keratoplasty.

Diffuse epithelial ingrowth was observed in 2 patients after perforating keratoplasty. Both cases involved a corneal graft after perforating injury with aphakia. In the first patient, the epithelial invasion was probably stimulated by a spatula synecholysis. In this case, the diagnosis was only made by histological investigation after enucleation. In the second patient the epithelial ingrowth was observed 8 months after keratoplasty. The clinical diagnosis was made on the basis of the typical slitlamp findings. In this case, the epithelial invasion led to hypotension with high resistance of outflow measured by electrotonography. In a very close chronological relation to the probable fall of chamber fluid secretion, development of a band-shaped keratopathy was observed.

Adult↗
PubMed1986

[Immune reactions following keratoplasty].

On the basis of follow-up examinations of 236 penetrating keratoplasties the different forms of immune reaction were analyzed with special regard to their relationship to indication and prognosis. An immune reaction was observed in 42.8% of the cases. An epithelial Khodadoust line occurred in 17 transplants (7.2%). Nine of these were early reactions within the first two months after reoperation. Subepithelial infiltrates occurred in 14 grafts (5.9%), usually as late complications except after reoperation. Special risk factors are anterior synechiae, chronic inflammation and regrafts. The lower risk group differs from the high risk group with regard to a) the epithelial Khodadoust line (2.9% vs. 10.6%), b) the severs forms of endothelial immune reactions (4.8% vs. 32.6%), and c) the irreversible immune reactions (0% vs. 23.5%). Subepithelial infiltrates and mild forms of precipitates occurred about equally in both groups. The different forms of endothelial immune reactions are of prognostic value only in connection with the individual diagnosis and indication. About 50% of the late immune reactions were of iatrogenic origin. Misalignment of the graft can lead to a typical Khodadoust line. In one patient an irreversible immune reaction of the diffuse type was caused by YAG laser treatment of a secondary membrane.

Cornea↗
PubMed1983

[Therapeutic soft lenses following keratoplasty, indications and complications].

A reported on 27 eyes (25 patients) which were fitted with soft permanent lenses following penetrating keratoplasty. The eyes were divided into three groups, according to the nature of the epithelial damage caused by the lens: 1) mechanical damage; 2) primary damage to the endothelium with secondary epithelial resistance. In 52% of the cases superficial neovascularization occurred, but this did not lead to serious complications. In the first and second groups, infiltrates were only seen after longterm use. The highest rate of complications, with infiltrates occurring relatively early and with liquefaction, was observed in the third group. In the first group the permanent lens led to lasting stabilization of the condition with a relatively low risk. In the second group the lens brought freedom from complaints with complications occurring only after 1-2 years. In the third group it was found that complications with negative courses may arise after only a short time.

Contact Lenses, Hydrophilic↗
PubMed1981

Bilateral acute vascular retinal necrosis.

In this paper we report on a patient with obliterative retinal vasculitis which, within a few weeks, led to retinal necrosis with fibrous alterations of the central parts of the retina and annular retinal tears in the periphery. The clinical picture is interpreted as bilateral acute retinal necrosis, corresponding to earlier reports in the literature. Our patient differs from the case reports known to us so far in the purely obliterative-vascular progress form of retinal necrosis, the lack of uveal involvement, the presence of unilateral labyrinthine deafness (probably of vascular origin), and the demonstration of pronounced cerebral atrophy.

Adult↗
PubMed1980

[Renal osteodystrophy in children. Therapy with 1,25-dihydroxy-cholechalciferol (author's transl)].

Growth arrest and renal osteodystrophy are major problems in renal insufficiency of children. The present report describes our experiences in managing renal osteodystrophy in 14 dialyzed children using 1,25-DHCC for 12 months. Values in plasma of Ca, P, Mg, alkaline phosphatase, iPTH, 25-OH-D, and 1,25-DHCC were determined regulary. Skeletal X-rays and analysis of iliac crest biopsies were obtained in each child. In treatment with 1,25-DHCC episodes of severe but reversible hypercalcemia occurred. Alkaline phosphatase and iPTH normalized completely. Radiographic examinations revealed marked improvement. Histological signs of fibro-osteoclasia and resorptive defects disappeared but there was no recovery of osteomalacia. A reduction of osteoblast population and of bone transformation was obvious. 1,25-DHCC failed to normalize growth in uremic children. In short, neither vitamin D nor 1,25-DHCC can guarantee complete recovery of renal osteodystrophy and growth arrest in uremic children.

Adolescent↗
PubMed1979

[Corneal deposits in children on dialysis and treatment with vitamin D3 and 1,25 DHCC (author's transl)].

The corneas of 15 children on intermittent long-term dialysis for renal failure were studied, first during a period of treatment with high doses of vitamin D3 and subsequently during a study with the vitamin D metabolite 1,25 DHCC. Metastatic calcification of the limbus or increased limbic deposits only occurred during the second treatment phase, with vitamin 1,25 DHCC. In 5 of these children phases with plasma calcium levels were recorded which were closely related to the times when corneal changes occurred. In 3 children phosphate values were also increased. Only one child presented with normal calcium values and merely an increase in phosphate concentration. Regression of corneal deposits following normalization of calcium metabolism seems possible in the light of observations so far.

Adolescent↗
PubMed1979

Renal bone disorders in children: therapy with vitamin D3 or 1,25-dihydroxycholecalciferol.

Twelve children with chronic renal failure (CRF) and sixteen children receiving regular dialysis therapy (RDT) were treated with between 10,000 and 50,000 IU of vitamin D daily. This was associated with an increase in serum calcium levels and reduction in PTH levels. In the children with CRF, secondary hyperparathyroidism was improved with treatment but its development was not completely prevented nor was healing complete. In the patients receiving RDT, treatment with vitamin D improved the changes associated with secondary hyperparathyroidism in 50% of cases but these features sometimes reappeared despite continuing treatment. Hypercalcaemia or metastatic calcification was not seen. Subsequently, 1,25(OH)2D3 was administered to 14 children receiving RDT. This was associated with the return of serum calcium levels to normal, inhibition of PTH synthesis and an improvement in intestinal calcium absorption. Fibro-osteoclasia was cured and there was improvement in actual bone resorption. There was also improvement in osteoidosis in those children who showed disturbances of mineralisation. Calcification in the limbus area of the eyes may occur and hypercalcaemia was seen commonly. Treatment with 1,25(OH)2D3 should only be offered to children with severe renal bone disease. Neither vitamin D3 nor 1,25(OH)2D3 can guarantee complete recovery of osteodystrophy and of growth arrest in uraemic children.

Adolescent↗