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Biomedical subjects

V Klauss

Publications and source records attributed to V Klauss.

At least 109 records · Page 6Linked to original sources
PubMed1995

Sicca syndrome in patients infected with the human immunodeficiency virus.

PURPOSE: To investigate an association of the severity of the human immunodeficiency virus (HIV) disease with decreased tear production in a controlled setting. PATIENTS AND METHODS: Seventy-two patients (144 eyes) and 30 age- and sex-matched control subjects (60 eyes) were studied prospectively. Tear production was measured using the Schirmer I test (measured in millimeters after 5 minutes). Patients were classified into three clinical groups: asymptomatic HIV infection, lymphadenopathy syndrome (LAS) or acquired immune deficiency syndrome (AIDS)-related complex (ARC), and AIDS. Additionally, patients were classified according to the CD4+ lymphocyte count. RESULTS: Tear production (mean +/- standard deviation) did not differ (P = 0.32) among eyes of patients with asymptomatic HIV infection (17.1 +/- 10.8; n = 14), LAS or ARC (18.3 +/- 10.3; n = 70), and AIDS (20.7 +/- 10.3; n = 60). In addition, mean tear production was not decreased significantly when comparing each clinical group with the control subjects (17.8 +/- 4.4). However, the relative frequency of eyes with significantly decreased tear production (< 9 mm) was 23.6% in all 144 eyes. In addition, the relative frequency of significantly decreased tear production did not differ (P = 0.52) between eyes of patients with asymptomatic HIV infection (35.7%), LAS or ARC (21.4%), and AIDS (24.1%). In addition, the relative frequency of significantly decreased tear production did not differ (P = 0.30) between eyes of patients with a CD4+ count of more than 400 cells/microliters (23.1%; n = 26), 400 to 200 cells/microliters (31.3%; n = 48), 200 to 50 cells/microliters (14.3%; n = 42), and less than 50 cells/microliters (21.4%; n = 28). CONCLUSION: The authors data show that decreased tear production occurs in approximately 20% to 25% of patients with HIV infection. This increased frequency of decreased tear production is not associated with the CD4+ count, or related to the severity of HIV disease, respectively. The possibility of an autoimmune-like pathogenesis of abnormalities of tear production in patients with HIV infection should be studied intensively.

Adult↗
PubMed1995

[Ocular microangiopathy syndrome in patients with AIDS is associated with increased plasma levels of the vasoconstrictor endothelin-1].

OBJECTIVE: Ocular microangiopathic syndrome is the most frequent ophthalmic finding in patients suffering from the acquired immunodeficiency syndrome (AIDS). Ocular microvascular changes including cotton-wool spots are closely associated with neuroretinal and cognitive deficits in patients infected with the human immunodeficiency virus type 1 (HIV-1). Endothelin-1 is a recently identified cytokine with potent vasoconstrictor activity which is associated with various diseases involving vascular structures. METHODS: We studied 29 patients with AIDS by indirect ophthalmoscopy and by slit lamp biomicroscopy, and endothelin-1 immunoreactivity (IR) was measured in plasma by radioimmunoassay. Cotton-wool spots were counted as indicator of retinal microvasculopathy. Conjunctival bloodflow sludging in conjunctival vessels was measured by a standardized rating scale as indicator of conjunctival microvasculopathy. Parameters of immunosystemic damage were determined as covariates. RESULTS: Endothelin-1 IR was closely associated with the number of cotton-wool spots (Spearman r = 0.53, p < 0.01) and with the extent of conjunctival blood-flow sludging (r = 0.61, p < 0.001). The level of significance became stronger applying analysis of covariance with Endothelin-1 IR as dependent variable and number of cotton-wool spots (p < 0.0001) or extent of conjunctival blood-flow sludging (p < 0.0001) as independent variables. CONCLUSION: Our data are consistent with the hypothesis that the vasoconstrictor endothelin-1 has an important role in the pathogenesis of HIV-1-related ocular microangiopathic syndrome. As HIV-1-related ocular microangiopathic syndrome is associated with neuroretinal and cognitive deficits in patients with HIV-1 disease the therapeutic use of endothelin antagonists currently under investigation should be discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Early pars plana vitrectomy without buckling procedure in cytomegalovirus retinitis-induced retinal detachment.

BACKGROUND: Retinal detachments induced by cytomegalovirus (CMV) retinitis can often be treated successfully with a buckling procedure combined with vitrectomy and silicone oil instillation, but this technique yields varying visual results. METHODS: To minimize operational trauma, pars plana vitrectomy and silicone oil instillation without additional buckling was performed in a series of 11 consecutive patients with acquired immune deficiency syndrome (AIDS) and CMV-retinitis-induced retinal detachment. Surgery was performed early in the course of the retinal detachment: 6 patients (55%) had an attached macula, and 7 patients (64%) had a visual acuity of 20/200 or better. RESULTS: After a mean follow-up period of 5 months (range, 1-9 months) 9 patients (82%) had a completely reattached retina and 9 patients (82%) had visual acuity of 20/200 or better. The macula was reattached in all patients. A localized detachment of the inferior retina was noted in 2 patients (18%), and a second operation was required in one eye. Significant cataract formation occurred in two patients during the follow-up period. Proliferative vitreoretinopathy and increased intraocular pressure were not observed. CONCLUSION: Early vitrectomy without additional buckling procedures is justified in patients with CMV-associated retinal detachment because it stabilizes the retinal situation without major complications and improves visual function.

AIDS-Related Opportunistic Infections↗
PubMed1995

Effect of growth hormone (hGH) replacement therapy on physical work capacity and cardiac and pulmonary function in patients with hGH deficiency acquired in adulthood.

The effects of 6 months of replacement therapy with recombinant human GH (hGH) on physical work capacity and cardiac structure and function were investigated in 20 patients with hGH deficiency of adult onset in a double blind, placebo-controlled trial. The GH dose of 12.5 micrograms/kg BW was self-administered daily sc. Oxygen consumption (VO2), CO2 production, and ventilatory volumes were measured during exercise on a bicycle spiroergometer. M-Mode echocardiography was performed using standard techniques. The VO2 max data, expressed per kg BW (mL/min.kg BW) showed a significant increase from 23.2 +/- 2.4 to 30.0 +/- 2.3 (P < 0.01) in the hGH-treated group, whereas the VO2 max data, expressed per lean body mass (milliliters per min/kg lean body mass) did not change significantly in either group. Maximal O2 pulse (milliliters per beat) increased significantly from 15.2 +/- 5.6 to 19.6 +/- 3.3 mL/beat (P < 0.01), but remained constant in the placebo group. The maximal power output (watts +/- SE) increased significantly (P < 0.01) from 192.5 +/- 13.5 to 227.5 +/- 11.5 in the hGH-treated group, but remained constant in the placebo group. Cardiac structure (left ventricular posterior wall, interventricular septum thickness, left ventricular mass, left ventricular end-systolic dimension, and left ventricular end-diastolic dimension) as well as echocardiographically assessed cardiac function did not change significantly after 6 months of treatment in either group. We conclude that hGH replacement in hGH-deficient adults improves oxygen uptake and exercise capacity. These improvements in pulmonary parameters might be due to an increase in respiratory muscle strength and partly to the changes in muscle volume per se observed during hGH replacement therapy. Furthermore, an increased cardiac output might contribute to the improvement in exercise performance during hGH treatment. According to our data, hGH replacement therapy leads to an improvement of exercise capacity and maximal oxygen uptake, but has no significant effect on cardiac structure.

Adult↗
PubMed1995

Human immunodeficiency virus-related microvasculopathy and Kaposi's sarcoma: a case-control study.

Ocular microangiopathic syndrome including retinal and conjunctival abnormalities is frequently found in patients with human immunodeficiency virus type 1 (HIV-1) disease. Kaposi's sarcoma (KS) is the most frequent neoplasia found in patients with HIV-1 disease. We have recently reported a significant association between conjunctival microvasculopathy and KS in 117 patients with HIV-1 disease. The objective of the present study was to determine whether this association is existent when matched patients with and without KS are compared. A total of 22 matched pairs were obtained under consideration of the absolute CD4+ lymphocyte count, Walter Reed (WR) classification, gender, and serum levels of beta-2-microglobulin and neopterin. Conjunctival microangiopathy was determined for each eye by a standardized rating scale ranging from 0 to 5, allowing a reliable and valid quantification of conjunctival blood-flow sludging. The mean value obtained for conjunctival sludge was 1.8 (SEM, 0.4) for patients without KS and 3.2 (SEM, 0.3) for patients with KS, demonstrating a clinically and statistically significant difference between the two groups (Student's t = 3.0; P = 0.003). This difference was higher when patients with a CD4+ lymphocyte count exceeding 200/microliters were regarded. Similar factors or mechanisms may contribute to HIV-related conjunctival microvasculopathy and KS.

Adult↗
PubMed1995

Myocardial contrast echocardiography for assessment of papaverine vasodilator response in patients with angiographically normal coronary arteries and in patients after orthotopic heart transplantation.

Myocardial contrast echocardiography has the potential for assessing changes in regional myocardial perfusion. We used this method to compare papaverine vasodilator response in 10 patients after orthotopic heart transplantation without acute rejection of left ventricular hypertrophy (HTX) and in 15 patients with angiographically normal coronary arteries (control group). Injections of 2 ml of sonicated iopromid (9 paired injections in HTX and 24 paired injections in the control group) were performed before and after intracoronary application of papaverine (8 or 10 mg) into the left or right coronary artery. From regional time-intensity curves, alpha (variable of curve width), area under the curve (area), peak contrast intensity (Imax) and contrast decay half-time (T1/2) were derived by from a gamma variate function. T1/2 increased from 4.2 +/- 1.2 to 7.2 +/- 4.0 s (p < 0.01) after papaverine in HTX compared to a change from 4.8 +/- 1.0 to 6.0 +/- 1.7 s (p < 0.001) in normal subjects. Alpha decreased in HTX from 0.44 +/- 0.15 to 0.27 +/- 0.10 s-1 (p < 0.01) after intracoronary papaverine injection. In the control group alpha was 0.37 +/- 0.08 s-1 at rest compared to 0.30 +/- 0.08 s-1 at hyperemic conditions (p < 0.002). Area increased in HTX from 444 +/- 261 to 910 +/- 732 U.s (p < 0.01) and in normal subjects from 352 +/- 171 to 585 +/- 262 U.s (p < 0.001). Hyperemic to baseline flow ratios for area varied from 0.9 to 3.8 (mean 2.17 +/- 1.11) in HTX compared to 1.76 +/- 0.52 (1.03 to 2.71) in normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Etiology of secondary glaucoma at university clinics in Munich and Nairobi].

Glaucoma is one of the most common blinding diseases worldwide. For early detection and treatment of this insidious ailment investigations of risk factors are necessary, most of which require extensive technically demanding and time consuming procedures. Basic information on risk factors for the development of glaucomatous damage is essential for diagnosis of glaucoma, for the identification of groups at risk, and for the planning of prevention and intervention programs. Epidemiological data on secondary glaucomas is especially scarce, while at the same time the strict distinction between primary and secondary glaucomas has been abandoned with changing pathophysiological rationale. We compared the distribution of the main causes of secondary glaucomas in the university eye clinics in Munich and Nairobi, with the aim of finding possible risk factors and obtaining basic information that might be used in preventive programs. We examined 150 patients in Munich and 132 in Nairobi in 1991 and 1992. In addition to tests of visual acuity and intraocular pressure, gonioscopy, ophthalmoscopic assessment of the optic disc and perimetry were performed. Eyes with intraocular pressures above 22 mmHg and a detectable causative condition were selected for the study. The average age of the patients in Munich was 65 years, and most of them presented with glaucoma caused by iris neovascularization (42%), followed by exfoliation syndrome (14%), intraocular inflammation (11%), trauma (10%) and preceding ocular surgery (9%). In Kenya patients were significantly younger, with an average age of 41 years. Here most glaucomas were posttraumatic (40%); 70% of these patients were aged under 30. Other causes were earlier operations (17%), inflammation (16%), lentogenous changes (10%) and neovascularizations (10%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Quality management, possibilities and chances in ophthalmology].

German legislation introduced in 1988 called for obligatory quality assurance (QA) practice to be initiated by health care providers. In 1992 the scope of the legislation was extended. Opportunities for introducing quality assurance practice in ophthalmology are demonstrated through examples. A necessary preliminary step to QA is to identify priority areas requiring action. A second necessary action entails the definition of quality indicators. Through their monitoring, these quality indicators allow identification of problem areas as reflected in the collected data. The final important phase of QA practice involves development of strategies to counteract identified problems. This process implies one or more cycles of: problem analysis, establishment of rectifying targets, actual intervention and finally evaluation of interventions made. Compulsory inter-hospital comparison of QA data calls for agreed standards within health care fields. In conclusions, QA practices in ophthalmology (with special reference to the pilot project on QA in cataract surgery) suggest that QA measures are well accepted by health care providers in this field.

Cataract Extraction↗
PubMed1995

[Variability of transplant vasculopathy. A study with intravascular ultrasound].

Cardiac allograft vasculopathy (CAV) influences long-term survival of patients after heart transplantation. Histopathology studies have demonstrated the insensitivity of coronary angiography (CA) for detecting CAV. Intravascular ultrasound (IVUS) is an imaging technique that provides qualitative and quantitative characterization of vessel wall morphology. The purpose of this study was to compare in vivo IVUS with coronary angiography in cardiac transplant recipients and to analyze intraindividual and segmental variability of CAV involvement. IVUS studies were performed at routine follow-up angiography in 33 patients 48 +/- 23 months after heart transplantation. 134 segments (1 to 8 per patient) were classified by IVUS according to a modified Stanford score (morphometric grading from 1 to 6). Patient characteristics and laboratory findings were further compared with intimal thickening. 114/134 (85%) segments were normal with CA. In 56% of these segments, IVUS revealed mild to moderate (IVUS grade 2 to 4, n = 45) or severe (IVUS grade 5 to 6, n = 19) intimal thickening. Mean IVUS scores between proximal and distal segments were not different (2.9 +/- 1.9 vs. 2.4 +/- 1.9, ns). Intimal thickening was more pronounced in segments of the LAD compared to the RCX (3.1 +/- 2.0 vs. 2.03 +/- 1.6, p < 0.01). In 39% of patients, the intraindividual extent of CAV was very heterogeneous (range: 3 to 5 IVUS grades). There was no significant correlation between IVUS and clinical or laboratory findings. IVUS is a sensitive method for the in vivo detection of CAV, while even severe intimal thickening can often not be identified by CA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Coagulase-negative staphylococci in normal and chronically inflamed conjunctiva].

UNLABELLED: This study examines the prevalence of coagulase-negative Staphylococcus species in normal and mildly inflamed conjunctiva, their sensitivity to antibiotics, and their relationship to the remaining flora. PATIENTS AND METHODS: In 99 patients including 9 HIV-positives in an early stage of the infection, 100 conjunctival swabs were taken and microbiologically investigated for bacteria and fungi. Thirty-four were from healthy eyes. 40 were from patients with chronic (n = 28) and unspecific (n = 12) conjunctivitis, 17 were from patients with a variety of outer inflammatory ocular conditions, and 9 were from the HIV group from uninfected (n = 6) and infected (n = 3) conjunctivae. Samples from each patient were collected with three moistened cotton swabs and directly inoculated onto five different agars, followed by immersion into three specific culture broths. Staphylococci were identified species-wise, the other microorganisms genus-wise. Sensitivity to a broad spectrum of antibiotics was determined by agar diffusion tests. OUTCOME: Staphylococci were found in 89%, which was the highest prevalence genus-wise. Of those, coagulase-negative species accounted for 86%, while coagulase-positive Staphylococcus aureus was isolated in 12% of all swabs. In the 86 smears positive for coagulase-negative staphylococci, 151 different strains were isolated. In these strains, resistance to the 13 tested antibiotics varied from 0% for vancomycin to 66% for penicillin. Strains which were isolated from patients with chronic conjunctivitis showed a greater range of resistance than those from normal flora, with significant levels for ciprofloxacin, gentamycin and kanamycin (Mann-Whitney) U-test: P < 0.05). All except six strains of staphylococci were identified strains represented ten species, of which Staphylococcus epidermidis was most prevalent (74%), but only made up 70% of all isolated strains of the coagulase-negative staphylococci. Staphylococcus aureus and gram-negative bacteria were found significantly more commonly in patients which chronic conjunctivitis than in healthy eyes, while coagulase-negative species of the Micrococcaceae family were significantly more prevalent in the healthy than in the chronically inflamed conjunctiva (chi-square: P < 0.05). CONCLUSION: The conjunctiva can simultaneously host several stems of coagulase-negative staphylococci, which differ in regard to species and resistance to antibiotics. This variety might indicate a microbiological balance of the conjunctiva and be reduced in chronic inflammatory conditions. In patients with chronic conjunctivitis the risk for multiresistant coagulase-negative staphylococci is increased.

AIDS-Related Opportunistic Infections↗
PubMed1994

Endothelin-1 immunoreactivity in plasma is elevated in HIV-1 infected patients with retinal microangiopathic syndrome.

Endothelin-1 is a recently identified cytokine with potent vasoconstrictor activity which is associated with various diseases involving blood vessels. HIV-1 related retinal microangiopathic syndrome is a frequent finding in patients with AIDS or AIDS-related complex, presenting predominantly with retinal cotton-wool spots. We investigated 55 HIV-1 infected patients by ophthalmoscopy and for endothelin-1 immunoreactivity in plasma and an additional 76 HIV-1 infected patients only for endothelin-1 levels. For reference values 13 age-matched healthy subjects were studied. In 18 of 55 patients (33%) investigated ophthalmoscopically we found evidence of microangiopathic syndrome. Overall, the mean endothelin-1 immunoreactivity in plasma of HIV-1 infected patients was significantly elevated as compared to controls (4.28 +/- 3.62 versus 2.72 +/- 0.67 fmol/ml, P < 0.0001). HIV-1 infected patients with retinal microangiopathic syndrome had significantly higher plasma levels of endothelin-1 immunoreactivity (4.59 +/- 1.38 fmol/ml) compared to HIV-1 infected patients without microangiopathic syndrome (3.18 +/- 1.64 fmol/ml, P = 0.003). Correlation analysis revealed that endothelin-1 immunoreactivity in plasma had no significant association with disease progression, CD4 cell count, beta 2-microglobulin, neopterin, or age. Endothelin-1 immunoreactivity in plasma was correlated exclusively with retinal microangiopathic syndrome in one or both eyes (r = 0.45, P = 0.0006) and with the number of cotton-wool spots (r = 0.50, P = 0.0001). In conclusion, HIV-1 related retinal microangiopathic syndrome is associated with elevated plasma levels of endothelin-1. By virtue of its potent vasoconstrictor activity endothelin-1 may be involved in the pathogenesis of HIV-1 related vascular disease.

Adult↗
PubMed1994

Volumes and Na+/H+ antiporter activity of lymphocytes in patients with congestive heart failure.

Previous studies in patients with congestive heart failure (CHF) treated with diuretics and/or digoxin have shown abnormalities of cellular volume and electrolytes in biopsies of skeletal muscle. These abnormalities seem to play an important role with regard to the dysregulation of peripheral vascular resistance and characteristic clinical features of CHF, for example, muscular weakness. This study assessed the effect of angiotension-converting enzyme (ACE) inhibitor therapy on cell volume and cell volume regulation in patients with CHF. Cell diameters of human mononuclear leukocytes (HML) were determined electronically by a Coulter Counter. Cell diameters for 19 patients with decreased left ventricular ejection fraction (determined via levocardiography) on therapy with ACE inhibitors (group 1) were compared to those of HML from patients on diuretics alone (group 2, n = 16). The activity of the Na+/H+ antiporter was determined by cell swelling in isotonic propionate. The control group consisted of 20 normal, age- and sex-matched volunteers. HML diameters were significantly increased from 7.16 +/- 0.07 in normals to 7.24 +/- 0.08 microns (group 1; P < 0.01) and 7.23 +/- 0.11 microns (group 2; P < 0.05), indicating an abnormal regulation of cell volume. There were no statistically significant correlations between the individual ejection fraction or digoxin therapy and average cell diameters. In both patient groups ethylisopropylamiloride-sensitive swelling rates were normal compared to the control group indicating a normal activity of the Na+/H+ antiporter. In conclusion, increased cell sizes reflect a structural change in HML rather than a rapidly reversible functional abnormality which was not affected different by ACE inhibition and diuretic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Ultrasound guidance of Palmaz-Schatz intracoronary stenting with a combined intravascular ultrasound balloon catheter.

BACKGROUND: Coronary stenting in conjunction with coronary angioplasty is a valuable tool for treatment of severe coronary dissection and is effective in reducing the frequency of restenoses. Evidence is increasing that the lumen gain within the stent is negatively correlated with the rate of subacute closures and restenoses. Since the assessment of radiolucent coronary stents and complex lumen morphologies by angiography is limited, we hypothesized that the use of a balloon catheter with integrated intravascular ultrasound (IVUS) facility for stent deployment and guidance of its expansion could improve the acute lumen gain without relevant procedural prolongation. METHODS AND RESULTS: Deployment of a single Palmaz-Schatz coronary stent with the combined imaging balloon catheter alone was successful in 18 of 20 patients eligible for this study. Corresponding measurements of minimal lumen diameter (MLD) by angiography and IVUS could be performed in 16 patients, revealing a close correlation between the two methods within the reference segments (3.10 +/- 0.38 and 3.08 +/- 0.43 mm, r = .79). Despite an adequate angiographic result in most patients after stent deployment, IVUS showed smaller MLD within the stented segment (2.15 +/- 0.23 mm) compared with angiography (2.63 +/- 0.26 mm, P < .0001) with a poor correlation (r = .27). To achieve IVUS criteria for optimal stent expansion (ratio of 0.9 between IVUS-assessed cross-sectional area of stent and reference segment), an average of three additional balloon inflations with higher pressure and/or a larger balloon diameter were performed without adverse effects in 15 of 16 patients who initially did not fulfill these criteria. This resulted in a significant increase in stent MLD to 2.63 +/- 0.27 mm (IVUS, P < .0001 versus initial MLD) and 2.89 +/- 0.32 mm (angiography, P < .0002 versus initial MLD) and a better correlation between the two methods (r = .60). The IVUS guidance led to a 40 +/- 15% increase of the minimal stent cross-sectional area with an additional time consumption of 21 minutes on average. CONCLUSIONS: This study demonstrates the application of a combined imaging balloon catheter for delivery and ultrasound-guided expansion of Palmaz-Schatz coronary stents. IVUS offered a comprehensive insight into the stented coronary segments, revealing a substantial overestimation of stent dimensions by angiography. IVUS guidance led to a significant improvement of stent expansion. This additional lumen gain, which was not discernible by angiography in most patients, might result in a reduction of subacute stent thromboses as well as restenoses.

Adult↗