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K G Schmidt

Publications and source records attributed to K G Schmidt.

At least 37 records · Page 2Linked to original sources

Chromosome aberrations in adult Hodgkin disease in a Danish population-based study.

During a 6-year period, 31 patients with Hodgkin disease (HD) were analyzed for chromosome aberrations on lymphoid tissue. We obtained metaphases in 87% (27/31). The number of cells analyzed per case ranged from 17 to 31 (median 25), and the number of abnormal mitoses was between 1 and 17 (median 6). Chromosome aberrations were found in 59% (16/27). Numerical aberrations involved all chromosomes. The most frequently gained chromosomes were numbers 2 and 9, and the most frequently lost were numbers 10, 16, 21, 22, and X. Chromosomes most frequently involved in structural aberrations were numbers 1 and 6. The most frequent subgroups were nodular sclerosis (NS) (n = 16) and mixed cellularity (MC) (n = 10). Six NS patients and 8 patients with MC showed an abnormal clone. For the NS patients with an abnormal karyotype, 4 of 6 had a gain of chromosome 2, and all had structural aberrations of chromosome 1. Of the 6 MC patients, where a partial analysis was possible, 4 had a gain of chromosome 9, 2 had structural aberrations involving chromosome 6 and 2 of chromosome 14. In 1 case a translocation normally associated with non-Hodgkin lymphoma (NHL) was found (t[11;14]), whereas other translocations characteristic of NHL, such as t(8;14), t(14;18), and t(2;5) were not observed. A review of the literature on cytogenetic investigations in HD performed on lymphoid tissue showed that the most frequently gained or lost chromosomes were 1, 2, 5, 9, and 12 for NS and 2, 5, and 9 for MC. The most frequently affected chromosomes in structural aberrations were 1 and 6 for NS, and 1, 7, and 14 for MC. Involvement of chromosome 1, 6, and 14 in structural aberrations is characteristic of lymphoid neoplasms, as are the most frequently involved bands (1p36, 6q21-q26, 14q11, and 14q32) further supporting a B- or T-cell origin of the neoplastic cell in HD. The high hyperploidy seen in HD is not a frequent observation in NHL. Although certain chromosome aberrations seem to be characteristic of HD as opposed to NHL, specific nonrandom aberrations have yet to be identified. The rather low number of abnormal mitoses found in most HD cases underlies the importance of analyzing a large number of metaphases.

Adult↗

[Serous central chorioretinopathy. Acute autofluorescence of the pigment epithelium of the eye].

PURPOSE: The lack of histopathological material has placed limitations on our knowledge on lipofuscin in central serous chorioretinopathy (CSCR). This study was designed to document the pathological changes of the retinal pigment epithelium (RPE) in CSCR using in vivo recording of fundus autofluorescence. METHODS: Fundus autofluorescence was documented in 62 eyes of 44 subjects with CSCR using a laser scanning ophthalmoscope (Zeiss, Oberkochen; excitation wavelength: 488 nm, barrier filter at 521 nm). Images were compared to the respective fundus appearance and fluorescein angiograms. RESULTS: Neurososensory retinal detachments showed diffuse increased autofluorescence corresponding to the detached area. Long-standing lesions showed very irregular autofluorescence with regions greater and less than the background levels of autofluorescence. CONCLUSION: Focal accumulation of autofluorescent material occurs at the level of the RPE in patients with CSCR, relating to variation in metabolic activity of the RPE. This technique may be useful in selecting patients for laser photocoagulation.

Adult↗

Effect of topical dorzolamide on optic nerve head blood flow.

PURPOSE: The topical carbonic anhydrase inhibitor dorzolamide has proven effective in lowering intraocular pressure in glaucoma patients. Because an impaired blood supply of the optic nerve has to be regarded as a major pathogenic risk factor it seems important to examine the effect of this new antiglaucomatous drug on capillary optic nerve head blood flow. METHODS: In a double-masked, randomized clinical trial, dorzolamide eye drops were applied to both eyes of 15 healthy subjects (8 female, 7 male, mean age 30.6 years) three times daily for 3 days. The control group (15 healthy volunteers, 9 female, 6 male, mean age 30.8 years) received a placebo preparation according to the same protocol. Intraocular pressure (IOP), blood pressure, heart rate, capillary optic nerve head blood flow and retinal blood flow were measured at baseline (1D0), 90 min after single instillation (1D90), and after 3 days of therapy (3D). Scanning laser Doppler flowmetry (Heidelberg Retina Flowmeter) and laser Doppler flowmetry according to Riva (Oculix 4000) were used to measure optic nerve head blood flow. RESULTS: IOP dropped in dorzolamide-treated subjects from 12.5 mmHg to 11.0/10.5 mmHg (1D0, 1D90, 3DO) and in the control group from 13.0 mmHg to 12.5/12.5 mmHg. Optic nerve blood flow as measured by scanning laser Doppler flowmetry showed no significant changes in dorzolamide-treated volunteers (temporal 310/329/315 AU, nasal 387/402/399 AU) or in the placebo group (temporal 238/306/276 AU, nasal 356/382/379 AU). Also as measured by laser Doppler flowmetry optic nerve head blood flow did not show significant changes in dorzolamide-treated volunteers (temporal 12.98/12.6/11.7 AU, nasal 16.6/16.9/15.7 AU) or in the placebo group (temporal 11.9/12.4/12.4 AU, nasal 16.1/15.8/17.7 AU). The systemic parameters blood pressure and heart rate remained unchanged during the treatment period. CONCLUSION: The results showed the expected drop in IOP. However, capillary optic nerve head blood flow, measured by two different techniques, did not change during therapy. This may be due to the effective autoregulation in human optic nerve head circulation, which seems not to be affected by dorzolamide.

Administration, Topical↗

Cardiac function and structure in patients with chronic renal failure.

The long-term consequences of cardiac alterations in children with chronic renal failure (CRF) and after renal transplantation (TX) are largely unknown. Studies in adults with end-stage renal disease (ESRD) assume that the fate of many pediatric patients is determined by a high cardiovascular morbidity and mortality. This review describes clinical manifestations, pathophysiology, cardiac function and structure, and management of heart disease in children with CRF and post transplant. Echocardiography and Doppler ultrasonography allow differentiation of three functional disturbances: hypercirculation, systolic left ventricular (LV) dysfunction, and diastolic LV dysfunction, in addition to analysis of LV size and myocardial mass. From adult studies LV hypertrophy is recognized as an early prognostic marker of cardiovascular disease. It is present in about half of children with ESRD and after TX. It may regress, at least in part, by control of hypertension, hypervolemia, and anemia. Experimental studies have shown that, independent of these hemodynamic complications, uremia is associated with structural abnormalities of the heart, which were also described in adult patients with ESRD. These lesions consist mainly of hypertrophy of cardiomyocytes, interstitial fibrosis, and vascular changes (rarefied capillaries, thickened arteriolar walls). Cardiac complications in children with CRF and after TX deserve regular clinical and echocardiographic monitoring in order to minimize later cardiovascular morbidity by appropriate treatment.

Adolescent↗

[Ocular pulse amplitude, intraocular pressure and beta blocker/carbonic anhydrase inhibition in combined therapy of primary open-angle glaucoma].

BACKGROUND: Beyond intraocular pressure (IOP, German abbreviation: IOD) ocular perfusion is increasingly discussed in the pathogenesis of the glaucomas. The present study was designed to investigate for ocular pulse amplitude (OPA) in primary open angle glaucoma patients with elevated intraocular pressure (POAG, German abbreviation: POWG) following application of timolol, a beta-blocker and dorzolamide a topical carbonic anhydrase inhibitor. METHODS: OPA (Ocular Blood Flow System, OBF Labs U.K.) IOP, heart rate, systolic and diastolic brachial artery pressures were measured before and 4 weeks following application of timolol and additional 4 weeks following application of a timolol/dorzolamide combination in 14 POAG patients. RESULTS: Following administration of timolol, IOP was highly significantly reduced in drug treated POAG eyes; this effect was additively enhanced by dorzolamide. Timolol did not affect OPA, whereas dorzolamide significantly increased OPA in drug treated POAG eyes. Systemic perfusion parameters were unchanged. CONCLUSION: Timolol and dorzolamide drastically reduced IOP, in addition dorzolamide increased OPA in POAG, an ocular microcirculatory effect which may further help to improve prognosis of POAG.

Adrenergic beta-Antagonists↗

[Heart failure in utero: diagnosis and therapy].

Over the past 15 years considerable advances in ultrasonography have made increasingly detailed evaluation of the human foetal heart feasible. Accordingly, the presence of cardiac failure can now be diagnosed in human foetuses during the last two thirds of pregnancy by foetal echocardiography. The underlying causes of foetal cardiac failure can be identified and prenatal treatment, if considered appropriate, can be monitored by ultrasonographic methods. Two-dimensional and M-mode echocardiography, as well as Doppler ultrasound, are equally important with respect to evaluation of foetal cardiac failure. Foetal echocardiography has contributed remarkably to broadening our understanding of the conditions and natural course of cardiac failure during prenatal life. In turn, this has led to an increasing readiness to consider new forms of prenatal treatment for foetal cardiac failure.

Diagnosis, Differential↗

[Studies of the distribution of lipofuscin in the retinal pigment epithelium using high-resolution TV laser scanning ophthalmoscopy].

BACKGROUND: The fundus autofluorescence imaging technique has been modified allowing improved image resolution (768 x 572 pixel). We present results of fundus autofluorescence studies using this technique. MATERIALS AND METHODS: Fundus autofluorescence was studied in 286 eyes of 143 patients with retinitis pigmentosa, macular dystrophies and age-related macular degeneration using a confocal laser scanning ophthalmoscope prototype (Zeiss, Oberkochen; excitation wavelength: 488 nm, cut-off filter at 521 nm). RESULTS: The spatial distribution of autofluorescence was different in all diseased eyes investigated compared to the normal pattern of fundus autofluorescence. Each disorder showed a specific fundus autofluorescence appearance. CONCLUSIONS: The advanced technique of imaging fundus autofluorescence allows detailed studies of the lipofuscin distribution. In vivo analysis of the dynamics of accumulation and degradation of lipofuscin in eyes with tapeto-retinal dystrophies and age-related macular disease may contribute to elucidation of the pathogenesis of these disorders.

Adolescent↗

Phasic flow events at the aortic isthmus-ductus arteriosus junction and branch pulmonary artery evaluated by multimodal ultrasonography in fetal lambs.

OBJECTIVES: We assessed the phasic flow and interaction between the pulmonary trunk and aortic isthmus flow at their junction in the lamb fetus in late gestation and also assessed the interaction of the left pulmonary artery branch. STUDY DESIGN: With echocardiographic and Doppler ultrasonographic and saline-contrast techniques, we studied 7 fetal lambs with arterial and venous catheters in place to assess direction, velocity, and timing of flow at the aortic isthmus, ductus arteriosus, and proximal left pulmonary artery. RESULTS: At the isthmus-ductus junction, ductus systolic flow occurred later (0.048 +/- 0.006 second, mean +/- SD) and accelerated more slowly than isthmus flow but with higher velocities (peak 70.7 +/- 7.1 vs 63.1 +/- 6.3 cm/s, velocity time integral 5.7 +/- 1.2 vs 4.5 +/- 1.3 cm, respectively; P <.001). There was a small degree of late systolic flow reversal and admixture from both sources. Signals from the left pulmonary arterial branch showed a sharp, brief systolic forward flow with a peak velocity of 48.8 +/- 9.1 cm/s, followed by late systolic and diastolic flow reversal with a peak velocity of 23.5 +/- 8.7 cm/s. CONCLUSION: The differences in the flow timing may be the result of different timing of ventricular contraction, resistances in the vascular beds, and ductus constriction, both anatomic and physiologic.

Animals↗

[Fundus autofluorescence in patients with hereditary macular dystrophies, malattia leventinese, familial dominant and aged-related drusen].

PURPOSE: The lack of histopathological material has placed limitation on our knowledge on the composition of focal deposits in eyes with macular dystrophies, malattia leventinese, dominant drusen and age related macular degeneration. This study was designed to study the composition of focal deposits in these eyes by documenting fundus autofluorescence in vivo. METHODS: Fundus autofluorescence was documented in 343 eyes of 199 subjects with macular dystrophies, malattia leventinese, dominant drusen and age-related macular degeneration using a laser scanning ophthalmoscope (Zeiss, Oberkochen; excitation wavelength: 488 nm, barrier filter at 521 nm). RESULTS: Autofluorescence of focal deposits was increased in eyes with macular dystrophies. In eyes with malattia leventinese and dominant drusen autofluorescence intensity of focal deposits showed a wide spectrum. In contrast, autofluorescence of age-related drusen was within normal limits. Background autofluorescence intensity was increased in eyes with macular dystrophies and within normal limits in eyes with malattia leventinese, dominant drusen and age-related drusen. CONCLUSION: The technique of in-vivo recording of fundus autofluorescence allows the differential diagnosis between macular dystrophies/malattia leventinese, dominant drusen/age related drusen when otherwise not possible.

Adult↗

[Ocular pulse amplitude during manipulation of systemic perfusion parameters].

BACKGROUND: The mechanism for the control of choroidal perfusion is unclear. The present study was designed to investigate for the effect of standardized alteration of systemic perfusion parameters on choroidal hemodynamics in healthy volunteers. METHODS: Intraocular pressure (IOP; German abbreviation: IOD), Ocular Pulse Amplitude (OPA), systemic blood pressure, and pulse rate were measured, and ocular perfusion pressure was calculated in 14 otherwise non-smoking, healthy volunteers prior to and following exercise and smoking. RESULTS: Exercise significantly (sig., p < 0.05) increased pulse rate, systolic blood pressure and ocular perfusion pressure, while it sig. (p < 0.05) reduced IOP and diastolic blood pressure. However OPA was not sig. (p > 0.1) affected by changes in these parameters. Smoking sig. (p < 0.05) increased systolic blood pressure, diastolic blood pressure, pulse rate, and ocular perfusion pressure but did not sig. (p > 0.09) alter OPA. CONCLUSION: Despite affecting ocular and systemic perfusion parameters, exercise and smoking did not alter OPA, suggesting functional isolation i.e. autoregulation of the choroidal and/or ophthalmic artery circulation.

Adult↗

[Peak pulse blood volume and topical antiglaucoma drugs in rhesus monkeys with experimental open angle glaucoma].

BACKGROUND: The present study was designed to investigate the effect of topical antiglaucoma drugs on Peak Pulse Blood Volume (PPBV; German abbreviation: PGBV) in cynomolgus monkey eyes without (CMNG; German abbreviation: RA-KTL) and with lasersurgically induced glaucoma (CMG; German abbreviation: RA-LHDG). METHODS: CMG unilaterally received 2-3 laser treatments so as to develop the lasered-eye glaucoma model. Intraocular pressure (IOP; German abbreviation: IOD) and Ocular Pulse Amplitude were measured and PPBV was determined until the glaucoma model had stabilized. Consecutively topical antiglaucoma drugs (epinephrine, paraaminoclonidine, pilocarpine, timolol) were investigated in 4-8 animals in CMNG and CMG eyes. RESULTS: IOP and PPBV were not significantly altered in CMNG. In the CMG eyes epinephrine and paraaminoclonidine did not significantly alter IOP or PPBV, whereas pilocarpine and timolol sig. (p < 0.01) reduced IOP and significantly (p < 0.05) increased PPBV. CONCLUSION: With respect to improved PPBV in the CMG eye the rank order of drug effectiveness is timolol > pilocarpine > paraaminoclonidine > epinephrine.

Animals↗

[Peak pulse blood volume in controlled modification of local perfusion parameters].

BACKGROUND: Choroidal autoregulation is discussed controversially. The present study was designed to investigate for the effect of standardized manipulation of local perfusion parameters on choroidal hemodynamics in cynomolgus monkey eyes with lasersurgically induced glaucoma (CMG; German abbreviation: RA-LHDG). METHODS: CMG unilaterally received 2-3 laser treatments so as to develop the lasered-eye glaucoma model. Intraocular pressure (IOP; German abbreviation: IOD) and Ocular Pulse Amplitude (OPA) were measured and Peak Pulse Blood Volume (PPBV; German abbreviation: PGBV) was determined. RESULTS: In CMG PPBV was not significantly (sig., p > 0.05) altered in laser-treated eyes--despite a sig. (p < 0.05) increase in IOP. Untreated contralateral control eyes of monkeys with an IOP-increase > 5 mm Hg in laser-treated eyes showed a sig. (p < 0.05) increase in PPBV. CONCLUSION: Unchanged PPBV in laser-treated eyes of CMG and an increase in PPBV in control eyes point at a bilateral autoregulatory compensatory mechanism, which is more manifest in eyes with IOPs in the normal range.

Animals↗

Management of intra-ocular foreign bodies impacting or embedded in the retina.

PURPOSE: To identify both the clinical features of eyes suffering penetrating ocular injury with intra-ocular foreign bodies (FB) impacting or embedded in the retina and the results of surgical outcome and complication rates. METHODS: Thirty-eight consecutive cases of penetrating ocular injuries with intra-ocular FB impacting or embedded in the retina were retrospectively analysed. RESULTS: The FB were metallic in 30 eyes (78.9%; 19 ferromagnetic) and were non-metallic in eight eyes (21.1%). Magnetic extraction was performed in 17 cases (44.7%) and instrumental extraction was performed in 21 cases (55.3%). In two cases, pars plana vitrectomy and FB removal was combined with penetrating keratoplasty, temporary keratoprosthesis and anterior segment reconstruction because of severe explosive injury to the eye. At the final postoperative examination, 32 eyes (84.2%) had completely attached retinas. Visual acuity (VA) improved postoperatively in 18 eyes (47.4%). A final VA of 0.5 or better was achieved in nine of 23 eyes (39.1%) with FB in the peripheral retina and in one of 15 eyes (6.7%) with posterior pole and/or optic nerve head involvement. There was no difference in the final VA regarding the time elapsed between trauma and the removal of the FB. CONCLUSION: The late anatomical and functional outcome in eyes with penetrating ocular injury and FB impacting or embedded in the retina is mostly uncertain, despite immediate and complex surgery. Final anatomical and functional outcome in the present study was influenced by location and extent of the initial damage to the posterior pole. The time that had elapsed between trauma and removal of the FB did not influence final visual function.

Adolescent↗

Topical carbonic anhydrase inhibition increases ocular pulse amplitude in high tension primary open angle glaucoma.

BACKGROUND: Ocular pulse amplitude (OPA) is reduced in normal tension primary open angle glaucoma (NTP) patients when compared with healthy age matched controls (CTL) while increased OPA appears to protect ocular hypertensive patients from visual field loss. If NTP is accompanied by vasospasm, as in roughly half of the primary open angle glaucoma (POAG) population (independent of intraocular pressure, IOP), calcium channel blockers increase OPA and thus stabilise visual fields in these patients. Current glaucoma drugs reduce IOP but do not activate (compromised) ocular perfusion. METHODS: The influence of dorzolamide, a topical carbonic anhydrase inhibitor in standard dosage (three times daily, one eye) on OPA, IOP, blood pressure, and heart rate was investigated in a randomised, prospective, masked clinical trial assessing the acute effects of dorzolamide v placebo before and 2 days after application in 33 cataract patients with (n = 14) and without (n = 19) high tension POAG (HTP) who provided informed consent. RESULTS: Following application of dorzolamide (D) IOP (mm Hg, mean (SEM)) in HTPD (20.2 (0.5)/16.3 (0.5) and in CTLD (16.0 (0.5)/12.3 (0.5)) was highly significantly (p < 0.001) reduced and was significantly (p < 0.03) reduced in vehicle (V) treated eyes (HTPv: 20.3 (0.4)/19.0 (0.4)) and CTLv: 15.8 (0.4)/14.9 (0.3)) when compared with respective baseline measurements. OPA (mm Hg) in HTPD (2.1 (0.1)/2.5 (0.1)) and CTLD (2.2 (0.1)/2.6 (0.2)) eyes was significantly (p < 0.05) increased and unaffected in vehicle treated eyes when compared with respective baseline measurements. Systemic perfusion variables were also unchanged. CONCLUSION: Dorzolamide increased OPA in HTP and CTL. Drugs stimulating OPA may improve prognosis of POAGs.

Aged↗

[Ocular pulse amplitude in ocular hypertension and open-angle glaucoma].

The present study was designed to investigate choroidal perfusion in primary open-angle glaucoma patients with statistically elevated (HPG) and statistically normal (NPG) intraocular pressure (IOP) and in ocular hypertensive volunteers (OHT) before and after application of topical antiglaucomatous drugs. When compared to age-matched healthy controls, ocular pulse amplitude (OPA) and IOP were significantly increased in OHT and unchanged in HPG; in NPG, the IOP was unchanged, and the OPA was significantly reduced. The topical antiglaucomatous drugs used in this study reduced IOP, but did not increase OPA. When compared to HPG and NPG, OHT subjects showed increased choroidal perfusion which may help to prevent glaucomatous optic nerve damage.

Administration, Topical↗

[Dynamics of accumulation and degradation of lipofuscin in retinal pigment epithelium in senile macular degeneration].

BACKGROUND: It is thought that lipofuscin plays a central role in the pathogenesis of age-related macular degeneration (AMD). The lack of histopathological material has been a severe limitation in our knowledge on lipofuscin in this disease. A new technique has been developed that allows in vivo imaging of fundus autofluorescence derived from lipofuscin in the retinal pigment epithelium (RPE) using a confocal Laser Scanning Ophthalmoscope (LSO). We studied the dynamics of lipofuscin accumulation and degradation in patients with AMD. MATERIALS AND METHODS: Serial examinations of the spatial distribution of fundus autofluorescence were performed in 148 eyes of 74 patients with AMD using a LSO over a period of 1-3.5 years. RESULTS: Fundus autofluorescence changed over time in almost all eyes studied. Areas of increased autofluorescence occurred progressively during follow up in eyes with drusen and hyperpigmentation. The size of pathologic autofluorescence increased over time in almost all eyes with geographic atrophy, subretinal neovascularisations and disciform scars. Irregular autofluorescence was seen over most subretinal neovascularisations. Autofluorescence intensity decreased in old subretinal neovascularisations and disciform scars over time. CONCLUSIONS: Changes of the distribution of autofluorescence occur in eyes with AMD over time. Fundus autofluorescence imaging allows in vivo analysis of the dynamics of accumulation and degradation of lipofuscin in the RPE in eyes with AMD and documentation of metabolic activity of the RPE.

Aged↗

Influence of the vasodilator drug isosorbide dinitrate on ocular circulation.

OBJECTIVE: To evaluate the ocular hemodynamic effects of the vasodilator drug isosorbide dinitrate. DESIGN: Randomized, prospective, controlled clinical trial assessing the short-term effects of 1 tablet containing 40 mg of isosorbide dinitrate vs placebo. SETTING: Department of Ophthalmology, University of Giessen, Germany. MAIN OUTCOME MEASURES: Systolic ophthalmic artery pressure (SOAP), systolic ocular perfusion pressure (SOPP), ocular pulsation amplitude (OPA), product of OPA x heart rate (HR), intraocular pressure (IOP), systolic and diastolic brachial artery pressure (SBAP and DBAP). Measurements were performed before and up to 7 hours after patients received the medication. PARTICIPANTS: Twenty healthy subjects (mean age, 28 years) who provided informed consent. RESULTS: After isosorbide dinitrate administration, SBAP, SOAP, and SOPP were significantly lowered (P = .01), and IOP tended to be lower (P = .08) compared with placebo. Maximum reduction was 3 to 5 hours after medication: SBAP was reduced by 10.9 mm Hg (9% reduction; P = .01), SOAP was reduced by 12.5 mm Hg (14% reduction; P = .01), SOPP was reduced by 11.3 mm Hg (14.5% reduction; P = .01), and IOP by 1.5 mm Hg (12% reduction; P = .08). The relation between SBAP and SOAP was significantly linear (P < .001), the correlation coefficient was 0.39. The DBAP remained unchanged, and the HR increased by 4 to 7/min (P = .08). The OPA and the product OPA x HR were significantly decreased (P < .001; P = .002) by maximum values of 44% and 40%, respectively. CONCLUSIONS: Administration of isosorbide dinitrate reduced SOAP and SOPP, reflecting reduced systemic systolic blood pressure. The decrease in OPA and the product OPA x HR (a measure of pulsatile ocular blood flow) may reflect a reduction in cardiac stroke volume typical for nitrates. Due to these hemodynamic effects and the minute reduction in IOP, the vasodilator drug isosorbide dinitrate, which has been proposed for glaucoma therapy, may be used only with caution in patients with glaucoma.

Adult↗