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Biomedical subjects

L L Hansen

Publications and source records attributed to L L Hansen.

At least 55 records · Page 3Linked to original sources
PubMed1997

Diameter of the optic nerve in idiopathic optic neuritis and in anterior ischemic optic neuropathy.

PURPOSE: There is considerable overlap in the clinical profile of patients with idiopathic optic neuritis (ON) and anterior ischemic optic neuropathy (AION). We tested the hypothesis that the retrobulbar diameter of the optic nerve may be a criterion for the differential diagnosis between ON and AION. METHODS: The diameter of the optic nerve was measured by B-scan ultrasonography with the eye in an abducted position. Only patients with a unilateral optic neuropathy were included, 16 ON patients (mean age 24 years, 5 with and 11 without disc swelling) and 9 patients with AION (mean age 72 years). As controls for the ON patients 10 young normal subjects (mean age 25 years) and as controls for the AION patients 10 elderly subjects with eye problems not related to the optic nerve (mean age 76 years) were examined. RESULTS: In the ON patients with disc swelling the diameter of the optic nerve was 5.4 +/- 0.5 mm in the affected and 3.0 +/- 0.3 mm in the unaffected side. This difference was significant (Wilcoxon-test, p = 0.043). In the ON patients without disc swelling the diameter of the optic nerve was 4.4 +/- 0.4 mm in the affected and 3.0 +/- 0.3 mm in the unaffected side. This difference was significant (Wilcoxon-test, p = 0.003). In the AION patients the diameter of the optic nerve was 3.0 +/- 0.3 mm on the affected and 2.8 +/- 0.4 mm on the unaffected side. This difference was not significant (Wilcoxon-test, p = 0.093). Comparing the optic nerves with ON and AION to those of the controls, the diameter was significantly enlarged in the nerves with ON and normal in the nerves with AION (one factor repeated ANOVA). CONCLUSION: The diameter of the optic nerve is increased in ON without disc swelling and even more so in ON with disc swelling. The enlargement is probably due to edema of the nerve itself, not the surrounding subarachnoidal space. In AION, the diameter of the optic nerve is normal. Measuring the diameter of the optic nerve by B-scan ultrasonography is particularly useful in the differential diagnosis between ON with disc swelling and AION.

Adolescent↗
PubMed1997

[Retinal hemorrhage in the infant as an indication of shaken baby trauma].

BACKGROUND: The shaken baby syndrome is a form of child abuse in young children. Typical are intracranial and intraocular bleedings. As external injuries are often missing, the shaken baby syndrome may easily be overlooked. Intraocular bleeding is a major diagnostic sign and can prove the diagnosis, if child abuse is suspected by the paediatrician. Thus critical family situations can be uncovered and long term help can be initiated. PATIENTS: Between 1991 and 1997 seven babies (age two to nine months) with intraocular bleedings were examined. Diagnosis, differential diagnosis and prognosis of the shaken baby syndrome are presented with these children. RESULTS: In two of the seven children a non-accidental trauma and shaken baby syndrome was obvious. In three cases the diagnosis of a shaken baby syndrome was most probable. In one child intraocular bleeding was possibly caused by a fall three months earlier. One child had retinal bleedings after resuscitation. In two cases a vitrectomy was performed. The follow up was two months to six years. In two children intraocular bleeding resolved completely, three children developed mild to severe amblyopia and two children became blind. Vitrectomy could not prevent loss of sight. CONCLUSIONS: Sudden cerebral symptoms or intraocular bleedings in otherwise healthy young children are suspicious for child abuse. A shaken baby syndrome has to be considered. Thus funduscopic examination in mydriasis is obligatory. The prognosis depends on the severeness of ocular hemorrhages and cerebral lesions.

Battered Child Syndrome↗
PubMed1996

Sensitive and fast mutation detection by solid phase chemical cleavage.

We have developed a solid phase chemical cleavage method (SpCCM) for screening large DNA fragments for mutations. All reactions can be carried out in microtiterwells from the first amplification of the patient (or test) DNA through the search for mutations. The reaction time is significantly reduced compared to the conventional chemical cleavage method (CCM), and even by using a uniformly labelled probe, the exact position and nature of the mutation can be revealed. The SpCCM is suitable for automatization using a workstation to carry out the reactions and a fluorescent detection-based DNA sequencing system to analyze the cleaved fragments.

Bacterial Proteins↗
PubMed1996

Effect of gossypol on cultured TM3 Leydig and TM4 Sertoli cells: 31P and 23Na NMR study.

The effects of gossypol on glucose metabolism, ATP levels and intracellular sodium levels in murine TM3 Leydig and TM4 Sertoli cell lines were investigated, and their response compared. Relative ATP levels and sodium ion levels in the two cell lines were determined by 31P and 23Na NMR spectroscopy. Short-term effect of gossypol on phosphate metabolism in immobilized and perfused cells was apparent in 31P NMR spectra only with relatively high concentrations of gossypol, corresponding to about 40 times IC50. However, incubation with low gossypol concentrations markedly affected the energetic status of the cells, especially of the TM3 cells. Although inhibition of proliferation by gossypol was stronger with the TM4 cells, the decrease of intracellular ATP level and increase of sodium ion concentration were more pronounced in the TM3 cells. The growth-inhibitory effect of (-)-gossypol was stronger than that of (+)-gossypol, with the eudesmic ratio of 2-2.5. The enantioselectivity of the effect of gossypol on the energy metabolism of TM3 and TM4 cells was low, in contrast to the in vivo antispermatogenic effect, which was reported to be solely associated with (-)-gossypol. Inhibition of energy production in somatic testicular tissue is thus unlikely to be major cause of the antispermatogenic effect of gossypol.

Adenosine Triphosphate↗
PubMed1996

Clinical utility of cytomegalovirus urine cultures for ophthalmic care in patients with HIV.

BACKGROUND: The utility of cytomegalovirus (CMV) urine cultures was checked in patients with HIV (a) to identify those at risk for CMV retinitis and (b) to guide clinical decisions on treatment and prophylaxis of CMV retinitis. METHODS: HIV infected patients were tested for CMVuria by shell vial cell cultures. The prevalence of CMVuria was related to CD4 count, HIV risk group, and time before and after diagnosis of CMV retinitis. RESULTS: A total of 639 shell vial cell cultures were obtained from 266 HIV infected ophthalmic patients. Only 4% of all patients with a CD4 count > 400 x 10(6)/l shed CMV in their urine compared with 42% with a CD4 count < or = 50 x 10(6)/l. Twenty three of 25 patients with CMV retinitis had a CD4 count < or = 50 x 10(6)/l. Among 130 patients with a CD4 count < or = 50 x 10(6)/l (a) those who were CMVuric had a nearly sevenfold risk (p < 0.0001) of developing CMV retinitis (35%) compared with those who did not shed CMV in their urine (5%), and (b) CMVuria and CMV retinitis were more frequent in homosexuals (58%/25%) than in intravenous drug users (23%/15%). More than 1 year before diagnosis of CMV retinitis 18% of patients were CMVuric compared with 83% of patients who were CMV culture positive in the last 3 months. CMVuria under virustatic maintenance therapy is associated with worsening of retinitis in two thirds of cases. CONCLUSION: Ophthalmic screening of patients with HIV should include those with a CD4 count < or = 50 x 10(6)/l and focus on the subgroup with additional CMVuria. Screening of other patients can be dropped without undue risk in order to spare AIDS patients unnecessary hospital visits. CMVuria as a single finding, however, does not justify antiviral prophylaxis of CMV retinitis.

AIDS-Related Opportunistic Infections↗
PubMed1996

Pattern, flicker, and flash electroretinography in human immunodeficiency virus infection: a longitudinal study.

To study electroretinographic (ERG) changes in the course of human immunodeficiency virus (HIV) disease, 42 eyes without retinitis were examined twice or more. During 9.6 months of mean observation time the visual acuity did not change. We found progressive functional impairment for the first, second, and third neurons of the visual pathway: the pattern-ERG amplitude (retinal ganglion-cell function) decreased by 11%, the b-wave amplitude (bipolars mediated by Müller cells) decreased by 13%, and the a-wave amplitude (dominated by rods) diminished by 21%. The flicker amplitude (dominated by cones) decreased by 20%. All of the latter four changes were significant (P < 0.02). Damage to the retina in HIV infection cannot solely be explained by visible changes in HIV retinopathy.

Adult↗
PubMed1996

Immunological aspects of recombinant factor VIIa (rFVIIa) in clinical use.

Patients, receiving rFVIIa for treatment of bleeding disorders, have been followed for specific antibody formation. No antibodies against FVII were demonstrated in 170 patients, with hemophilia, or with acquired inhibitors to clotting factors. Of 6 FVII-deficient patients, one overdosed patient developed antibodies to human FVII. There was no indication of de novo formation of antibodies to potential contaminating foreign protein, which could be correlated to the rFVIIa treatment. Except for the FVII-deficient population, which may represent a risk group, rFVIIa appears to be immunologically safe for use in patient groups with bleeding disorders, including hemophilia A and B patients.

Animals↗
PubMed1995

[Motility and binocular function after radial episcleral buckle].

BACKGROUND: The incidence of motility disturbances induced by episkleral buckle operations for retinal detachment has been reported to range between 7 and 77%. We anticipated a relation between the buckle size and the incidence and extent of motility disturbances. PATIENTS AND METHODS: We examined 45 patients 2 to 4 years after successful retinal detachment surgery with a radial buckle. The buckle diameter was 3-11 mm. Patients were examined for diplopia and heterophoria in the primary position and in 20 degrees secondary and tertiary gaze deviations. Stereopsis was determined using the TNO plates. Refractive error and visual acuity were also measured. RESULTS: Heterophoria measurements in the various directions of gaze revealed a hypermotility in 22/45 cases. A hypomotility was encountered only in one of the 45 cases. In 40 of the 45 cases the field of binocular single vision had a radius of at least 20 degrees. 39 of the 45 patients had stereopsis (after macular detachment 17/22, without macular detachment 22/23). 7/32 patients with a buckle of > or = 5 mm reported on diplopia, but none of the 13 patients with a buckle of < or = 4 mm. Heterotropia in the primary position was found in one of the 45 cases. He had three buckles, a 10.5 mm buckle under the superior rectus muscle of one eye and a 4 and 7.5 mm buckle under the inferior oblique and rectus muscles of the other eye. The resulting vertical deviation was successfully treated with prisms. Motility disturbances in the upper field of gaze were found in 2 of 45 cases with buckles of 5 and 7.5 mm. Diplopia was not permanent in these cases. DISCUSSION: Hypermotility towards the position of the buckle may be explained by a deviation of the adjacent rectus muscles, after sharp preparation and shrinkage of the intermuscular septum. CONCLUSION: Since motility disturbances were encountered only with buckles of > or = 5 mm, small buckles (< or = 4 mm) should be applied whenever possible.

Adult↗
PubMed1995

[Computer controlled analysis of the optic papilla in patients with anterior ischemic optic neuropathy].

BACKGROUND: In patients with non-arteritic anterior ischaemic optic neuropathy disc parameters have been measured with a largely objective method (Optic Nerve Head Analyzer). We wanted to find out, whether the measurements of different disc parameters allow an assertion of predisposition to AION. METHODS: Measurements have been done with the Optic Nerve Head Analyzer (ONHA). In 25 patients with AION disc area and neuroretinal rim area was measured in the nonaffected fellow eye. The results were compared to those of 19 healthy subjects. In 12 of the 25 patients the disc structure of the AION-eye was measured over time with an average of 4 measurements in 16 months. RESULTS: 1) Disc area and neuroretinal rim area of the AION-eyes do not differ significantly from those of the healthy subjects. 2) Disc area and neuroretinal rim area of the healthy fellow eyes of the AION patients were not significantly different from those of the healthy subjects. 3) Measurements of disc parameters over time did not show significant differences between the parameters of the beginning of AION and after 16 months. CONCLUSIONS: Measurements of disc area and neuroretinal rim area with the Optic Nerve Head Analyzer do not allow assertions of predisposition to AION.

Adult↗
PubMed1995

[Reproducibility of measurements with the Heidelberg retina tomograph in fundus elevations].

PURPOSE: The Heidelberg Retina Tomograph (HRT) was intended to evaluate the optic nerve head. It is, however, also possible to measure retinal elevations. There are no systemic data on the reproducibility of HRT measurements of retinal elevations. We now provide such data. METHODS: 117 measurements in patients with diseases which are characterized by retinal elevations were analyzed with the HRT. We measured the "volume above surface" of the retinal elevations. Each patient was analyzed three times, and the coefficient of variation was calculated. RESULTS: The coefficient of variation was between 0.55% and 40.5%. Some 42% of the coefficients of variation were between 0% and 10%, 31% between 5% and 10%, 21% between 10% and 20%, and 6% larger than 20%. CONCLUSION: The reproducibility of the HRT measurements in retinal elevations is clinically sufficient. The relation between sufficient reproducibility and accuracy is discussed.

Diabetic Retinopathy↗
PubMed1994

[Risk factors of pseudophakic detachment].

UNLABELLED: The increase of pseudophakic retinal detachments has raised the question about its risk factors. According to the literature, complicated cataract surgery rarely contributes to pseudophakic retinal detachment. Nevertheless, we noted a high proportion of defects in the capsular barrier among our patients. We therefore reevaluated our charts for perioperative and epidemiologic risk factors for pseudophakic retinal detachment. PATIENTS: Seventy-six patients with pseudophakic retinal detachment after extracapsular cataract operation with intraocular lens implantation were referred to the Ophthalmology Department of Freiburg University between 1986 and 1991. Their case records were analyzed for possible risk factors for retinal detachment. RESULTS: When retinal detachment developed, posterior lens capsule was not intact in 52/76 eyes (68%), the highest rate published so far. In 37 eyes capsular rupture occurred during cataract surgery, in 16 eyes followed by vitreous prolapse and in 9 eyes with persistent vitreous incarceration. Three eyes had vitreous prolapse via zonula. In 10 eyes YAG laser capsulotomy preceded detachment, and in 2 eyes capsular rupture occurred during an aspiration procedure for secondary cataract. The high proportion of intraoperative capsular ruptures is understandable if we assume a 2% risk of intraoperative capsular rupture, followed by a 20-fold increase in retinal detachment. The latency between cataract surgery and retinal detachment was 22 months after uncomplicated surgery, after YAG laser capsulotomy 13.5 and after intraoperative capsular rupture 10 months (medians). CONCLUSION: Vitreal complications in cataract surgery facilitate the development of retinal detachment. The incidence of defect posterior capsules and vitreal complications among patients with pseudophakic retinal detachments can be explained by assuming a 10- to 20-fold increase in retinal detachments after these complications. In cases of capsular or zonular rupture, all means, including prophylactic vitrectomy of vitreal strands, should be used to avoid permanent vitreous traction. However, the rate of retinal detachments after YAG laser capsulotomies only minimally surpassed the rate after uncomplicated cataract surgery. The risk for retinal detachment is not determined so much by the capsular defect itself. It is determined rather by the circumstances in which it occurred and by the grade of vitreal disturbance.

Adult↗
PubMed1993

Method for determination of intracellular sodium in perfused cancer cells by 23Na nuclear magnetic resonance spectroscopy.

Changes of intracellular sodium concentrations are often an indication of disease or malfunction. In this work, shift reagent-aided 23Na NMR spectroscopic determination of intracellular sodium was adapted to measurements with perfused cells embedded in agarose gel threads. Ehrlich ascites tumor cells (EHR2) and their multidrug-resistant counterparts (EHR2/DNR+) were immobilized and perfused until the metabolic steady state had been reached as shown by 31P NMR spectroscopy. Subsequent addition of 5 mM dysprosium(III) bis(tripolyphosphate) to the perfusion medium caused a separation of extracellular and intracellular 23Na NMR signals, making quantification of the intracellular sodium possible. The dysprosium shift reagent was apparently nontoxic to the cells, as shown by the unchanged level of ATP and other intracellular phosphates. NMR visibility of the intracellular sodium was determined in suspensions of EHR2 and EHR2/DNR+ cells by treatment with digitonin; the increase of intensity of the extracellular sodium resonance observed after the digitonin treatment corresponded well (97 +/- 3%) to the sum of intracellular and extracellular sodium observed with intact cells prior to the digitonin treatment. The resistant EHR2/DNR+ cells contained a moderately higher intracellular sodium level than the wild-type EHR2 cells, 1.02 +/- 0.10 and 0.77 +/- 0.07 mumol Na/mg protein, respectively. Closely similar levels of intracellular sodium were found by flame photometry. Thus, 23Na NMR offers a reliable method for noninvasive quantification of intracellular sodium in perfused cancer cells.

Animals↗
PubMed1993

[Isovolemic hemodilution in central retinal vein occlusion in patients less than 50 years of age].

AIM--Aim of the study was investigation of the effect of isovolemic hemodilution in patients younger than 50 years on the course of central retinal vein occlusion (CRVO) and to compare these results with those of older patients with CRVO. PATIENTS AND METHODS--We performed a prospective study on 35 patients younger than 50 years who were suffering from a central retinal vein occlusion. These patients were all treated by isovolemic hemodilution and compared to a group of older patients with CRVO with the same treatment. RESULTS--About 66% of the younger patients were men compared to only 46% in older patients. At least two cardiovascular risk factors were present in 8.5% of the younger and 54% of the older patients. 16 eyes showed the ischemic, 19 the nonischemic type of CRVO, a similar distribution as in older patients. The course of the disease was more favourable in younger patients, although ocular complications may occur in ischemic CRVO. Isovolemic hemodilution did not change the initial visual acuity of eyes with nonischemic CRVO, but led to an improvement in 56% of the eyes with ischemic CRVO. This means only a minor difference to the course of CRVO in hemodiluted older patients. CONCLUSION--In general, there is no principal difference between the CRVO in younger and older patients, but the course is more favourable in younger patients. On the basis of these findings we recommend isovolemic hemodilution in younger patients with ischemic CRVO.

Combined Modality Therapy↗