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Biomedical subjects

K Lindemann

Publications and source records attributed to K Lindemann.

12 recordsLinked to original sources
PubMed2000

Endothelial-like cells derived from human CD14 positive monocytes.

In the present study, we show that endothelial-like cells (ELCs) can develop from human CD14-positive mononuclear cells (CD14 cells) in the presence of angiogenic growth factors. The CD14 cells became loosely adherent within 24 h of culture and subsequently underwent a distinct process of morphological transformation to caudated or oval cells with eccentric nuclei. After 1 week in culture the cells showed a clear expression of endothelial cell markers, including von Willebrand factor (vWF), CD144 (VE-cadherin), CD105 (endoglin), acetylated low-density lipoprotein (AC-LDL)-receptor, CD36 (thrombospondin receptor), FLT-1, which is vascular endothelial cell growth factor (VEGF) receptor-1, and, to a weaker extent, KDR (VEGF receptor-2). Furthermore, in these cells structures resembling Weibel-Palade bodies at different storage stages were identified by electron microscopy, and upon culturing on three-dimensional fibrin gels the cells build network-like structures. In addition, cell proliferation and vWF expression was stimulated by VEGF, and the endothelial cell adhesion molecules CD54 (ICAM-1), and CD106 (VCAM-1) became transiently inducible by tumor necrosis factor-alpha (TNF-alpha). In contrast, the dendritic markers CD1a, and CD83 were not expressed to any significant extent. The expression of CD68, CD80 (B7-1), CD86 (B7-2), HLA-DR and CD36 may also suggest that ELCs might be related to macrophages, sinus lining or microvascular endothelial cells. Taken together, our observations indicate that ELCs can differentiate from cells of the monocytic lineage, suggesting a closer relationship between the monocyte/macrophage- and the endothelial cell systems than previously supposed.

Antigens, Differentiation↗
PubMed2000

Two-dimensional granular flow in a vibrated small-angle funnel

We have studied the flow of a single layer of uniform balls in a small-angle funnel when it is vibrated parallel to the flow. Generally, we measured the flow rate as a function of a dimensionless acceleration Gamma. However, for sufficiently small outlet widths, the flow can jam so we also measured the elapsed times between balls and their correlations to study jam dynamics. In particular, we found that when the funnel angle beta was larger than approximately 4 degrees, a stable jam always formed for Gamma<1 and the flow stopped. For Gamma approximately 1-4, jams still occurred, but now they broke and reformed, although they could last approximately 100 s, resulting in long-time correlations in the flow. The elapsed time distributions in this case show distinct, possibly algebraic, tails. Beyond Gamma approximately 4, the flow no longer jammed and the flow rate became constant. The general behavior has been mapped out in a rough phase diagram.

Journal Article↗
PubMed1998

s-IgA and cytokine levels in whole saliva of Sjögren's syndrome patients before and after oral pilocarpine hydrochloride administration: a pilot study.

Previous investigations have found elevated levels of s-IgA in the parotid saliva and normal levels in submandibular saliva of patients with Sjögren's syndrome (SS). Fox et al. also found elevated levels of cytokines (i.e., IL-2 and IL-6) in serum, salivary epithelial cells and parotid saliva of patients with SS. The oral administration of pilocarpine hydrochloride stimulates whole and parotid salivary flow. The purpose of this study was to determine the levels of s-IgA and IL-2 and IL-6 in whole saliva before and after administration of pilocarpine hydrochloride in SS subjects. Ten definitively diagnosed SS subjects were enrolled in the study, as were ten controls (C). The mean age was 57.2 years and all subjects were female. Whole unstimulated saliva (WUS) was collected by standard techniques for 5 min, after which the volume and flow rate were determined (mean WUS: SS = 0.047 vs C = 0.480 ml/min). Samples were centrifuged and the immunoglobulin analysis performed on the supernatants by immunoreactivity in a double-sandwich technique as previously described by Rudney et al. Cytokine analysis was performed similarly utilizing commercially available kits from R&D Systems. The results as analyzed by pairwise t-tests revealed comparable levels of s-IgA in the saliva of the SS patients, as compared to controls at baseline (means +/- SEM: SS-IgA = 348.1 +/- 82.0 vs C-IgA = 284.0 +/- 65.1 micrograms/ml; NS). Whole salivary flow was significantly increased (328%) in the SS subject group 60 min after the administration of 5 mg pilocarpine hydrochloride (means +/- SEM: 0.0472 +/- 0.017 vs 0.1546 +/- 0.054 ml/min; P < 0.01). There was no significant change in the concentration of s-IgA in the SS subject group following the pilocarpine dose (means +/- SEM: SS-IgA = 439.9 +/- 121.2 microliters/ml; P = NS). There were elevated levels of IL-2 in the saliva of four out of the ten and IL-6 in two out of the ten SS patients, as compared to controls (means +/- SEM: SS-IL-2 = 127.8 +/- 11.4 vs C-IL-2 = 30.8 +/- 1.6 pg/ml and SS-IL-6 = 41.4 +/- 7.1 vs C-11.6 +/- 2.8 pg/ml). There was also a significant decrease in the concentration of IL-2 in the same four out of ten SS subjects following the pilocarpine dose (means +/- SEM: SS-IL-2 = 32.4 +/- 10.3; P < 0.01). These preliminary results indicate that s-IgA levels do not change with increased salivary flow following the administration of pilocarpine hydrochloride in patients with Sjögren's syndrome. While cytokines are elevated in the whole saliva of some SS patients, a decrease in IL-2 concentration may occur with increased salivary flow.

Administration, Oral↗
PubMed1998

Administration of the cytoprotectant amifostine.

This article provides guidelines for the use of amifostine (Ethyol, Alza Pharmaceuticals, Palo Alto, CA, and U.S. Bioscience, Inc., West Conshohocken, PA), a pancytoprotective agent approved for reducing renal toxicity associated with cisplatin administration in patients with advanced ovarian or non-small cell lung cancer. Pretreatment with amifostine reduces the incidence of serious and cumulative chemotherapy-induced toxicities, thus improving quality of life, and allows administration of optimal doses and scheduling of chemotherapy and radiation therapy, translating into improved survival. Practical guidelines for administration of amifostine are provided in an effort to ameliorate emesis, amifostine's principle side effect.

Amifostine↗
PubMed1993

[Cystoid macular edema and visual acuity with intracapsular cataract extraction and Choyce anterior chamber lens vs. extracapsular cataract extraction and posterior chamber lens in the partner eye].

A prospective study was conducted on 65 patients who had a cataract operation. One eye had intracapsular cataract extraction (ICCE) with a Choyce-IX anterior chamber lens (ACL) and the fellow eye extracapsular cataract extraction (ECCE) with a posterior chamber lens (PCL). To evaluate the cystoid macular edema (CME), a fluorescence angiogram was recorded on the day of discharge and after 6 months. The severity of the CME was classified in three stages (degrees I-III). At discharge, no eye had CME grade III. CME grade I or grade II was seen in the ICCE group in 23% and in the ECCE group in 7.6%. After 6 months one eye of each group showed CME grade III (1.5%). CME grades I and II were seen after ICCE in 13.8% and 7.8% while the eyes with ECCE presented CME in 6.1% of grade I and of grade II, respectively. Visual acuity (VA) in the eyes with grades I and II CME was the same as in eyes without CME. The VA (median) of the ICCE group was 0.8 and of the ECCE 0.7. Because of infection of the capsular bag (toxic lens syndrome), in one case the PCL together with the capsular bag had to be explanted after 7 months. As for visual acuity and clinically significant CME (grade III), there was no statistical difference between ICCE plus Choyce-IX ACL eyes versus ECCE plus PCL eyes in the same patient.

Aged↗
PubMed1984

[Total calcium or ionized calcium? A comparative study].

Determining ionized calcium after CO2 equilibration of serum with subsequent electronic conversion to pH 7.40 (Ca2+corr) gives a practicable value for the diagnosis of calcium metabolism. "Anaerobic" sampling, necessary for the measurement of the actual calcium ion concentration, is obviated. Protein or albumin concentration in serum and complex-bound calcium do not interfere. Comparison of sera from 54 patients with bone metastases or myeloma, as well as from 300 patients with other diseases, indicate that the sensitivity of Ca2+corr in the diagnosis of hypercalcaemia is about twice or three times that of total calcium and that the latter's specificity - at least when ignoring protein concentration - is unsatisfactory with 18-45% "falsely" reduced values.

Adult↗