Multiple hemangiomas and hemangiomatosis--risk factors and outcome over an eight year period.

INTRODUCTION: Hemangiomas are the most common tumors of infancy. Multiple cutaneous hemangiomas may be associated with the presence of hemangiomas in inner organs. However, there is little data on the risk factors for organ involvement and the outcome of a large sample of patients. PATIENTS AND METHODS: patients with 3 or more cutaneous hemangiomas were evaluated with regard to patient characteristics, distribution of hemangiomas, results of radiological abdominal/cerebral imaging, clinical course, and therapeutic approach. We analyzed the risk factors for organ involvement and complications/outcome. RESULTS: The average gestational week at birth was 32.8; radiological imaging showed liver hemangiomas in 13.5% and mesenteric lesions in 1 (1.9%) but no cerebral lesions. Preterm infants (p=0.02) and patients with high numbers of cutaneous hemangiomas (p=0.02) were at higher risk of organ involvement. A life-threatening event occurred in 1 patient (1.9%). None of the patients died. CONCLUSIONS: Organ manifestation is relatively common in patients with multiple hemangiomas, complications are rare, but potentially life-threatening. We recommend abdominal imaging for patients with 3 or more hemangiomas, especially in preterm infants.

[Merkel cell carcinoma--clinically often misjudged]. / Das Merkelzellkarzinom--klinisch oft verkannt.

Merkel cell carcinoma is a rare, rapidly growing, highly malignant dermal tumor which occurs preferentially on light-exposed skin in advanced age. The course of the disease is frequently characterized by the occurrence of lymph node metastases and local recurrences, even in the first year after removal of the primary tumour. The five-year overall survival rate is only about 65 %, despite rigorous therapy. The histological pattern is characterized by trabecular strands of small, uniform cells with large basophilic nuclei and typical neuroendocrine granules. The diagnosis is confirmed immunohistochemically by neuroendocrine and epithelial markers. The excision of the primary tumor is regarded as first-line therapy. Adjuvant radiatiotherapy is almost always indicated and should also include lymph node drainage. In the stage of nodal disease, a combination of excision and radiotherapy is recommended. Adjuvant chemotherapy can be applied in this stage, as in small-cell bronchial carcinoma. The prognostic advantage has, however, not been proven. Despite good response to radiatiotherapy and chemotherapy, with at least prolonged recurrence-free intervals, Merkel cell carcinoma is rarely curable at the distant metastasizing stage. Individually defined, aggressive treatment,including radiatiotherapy, may in future considerably improve the prognosis, especially in the early stages of the disease.

Multiple reversible MR signal changes caused by Epstein-Barr virus encephalitis.

This report presents the imaging findings of an unusual case of Epstein-Barr virus (EBV) encephalitis. A young man presented with a short-lasting history of febrile infection, neuropsychologic deficits, ataxia, and seizures. MR imaging revealed fully reversible signal intensities (T2, diffusion-weighted imaging with a decreased apparent diffusion coefficient) in the splenium of the corpus callosum and both posterior hemispheres. EBV infection must be added to the list of differential diagnoses of (reversible) splenial lesions.

Primary culture of microvascular endothelial cells from human benign prostatic hyperplasia.

BACKGROUND: Prostate growth seems to be influenced by paracrine factors like IL-6 originating from the microvascular endothelium. Therefore, our efforts were focused on the primary culture and behavior of microvascular endothelial cells (HPEC) derived from tissue of human benign prostatic hyperplasia (BPH). Until now, the isolation and culture of HPEC from BPH have not been reported. METHODS: BPH tissue was cut into small cubes and gently squeezed after incubation with dispase. HPEC were cultured from the resulting cell suspension after a stepwise selection by use of superparamagnetic beads coated with antibodies against endothelial specific antigens. HPEC were characterized by flow cytometry and immunohistochemistry. gamma-Glutamyl transpeptidase activity (specific for microvascular endothelium) was measured after dissolution of the HPEC with Triton X-100. After the incubation of HPEC either with ATP, VEGF, or TNF-alpha, the release of IL-6 was measured by enzyme linked immunosorbent assay (ELISA). RESULTS: HPEC showed a typical endothelial morphology. They were positive for von Willebrand factor, CD31, CD62E (after stimulation with TNF-alpha), alpha-actin and were negative for fibroblastic antigens and PSA. Proliferation was stimulated by vascular endothelial growth factor (VEGF). gamma-Glutamyl transpeptidase activity in HPEC was 6.3 microIU/microg protein, whereas in human umbilical vein endothelial cells (HUVEC) no gamma-glutamyl transpeptidase activity was detectable. The IL-6 secretion of HPEC was stimulated by VEGF and TNF-alpha, but not by ATP and bradykinin. CONCLUSIONS: For the first time, the primary culture of microvascular endothelial cells from BPH tissue was successfully performed. Our results suggest that HPEC may be actively involved in prostate growth, due to the secretion of regulatory factors such as IL-6.

Prognostic significance of the presence of erythroblasts in blood after cardiothoracic surgery.

In patients suffering from a variety of severe diseases the detection of erythroblasts in peripheral blood is associated with poor prognosis. However, as yet the prognostic significance of erythroblasts in the blood of patients after cardiothoracic surgery has not been assessed. In a retrospective study we analyzed the database of 2074 patients, of whom 87 died in hospital during the postoperative period. All patients underwent cardiothoracic surgery using a heart-lung machine. Together with erythroblasts in blood, age, sex, body mass index, preoperative ejection fraction, smoking, diabetes mellitus, type of operation, emergency surgery, renal deficiency, pulmonary hypertension, and endocarditis were considered. The postoperative mortality of patients with erythroblasts in peripheral blood (n=57) was 45.6% (n=26), being significantly higher (p<0.001) than the mortality of patients without erythroblasts (3.0%). None of six patients with more than 2000 erythroblasts x 10(6)/l survived. The postoperative detection of erythroblasts is highly predictive of death, the odds ratio after adjustment for the other known prognostic factors being 7.2 (95% confidence interval 3.4-15.1). Erythroblasts were detected for the first time on average 11 +/- 2 days (median: 7 days; n=57) after surgery and 8 +/- 2 days (median: 6 days; n=26) before death. The detection of erythroblasts in blood after cardiothoracic surgery has a high prognostic significance in terms of in-hospital mortality, helping physicians to identify patients at high risk of death. This finding has to be confirmed by a prospective study with the use of a more sensitive and reliable technology and prospectively defined time intervals for counting blood cells.

In vitro modulation of steroid 5alpha-reductase activity by phospholipases in epithelium and stroma of human benign prostatic hyperplasia.

Membrane components, such as phospholipids, play an important role in the regulation of prostatic 5alpha-reductase activity. To describe in more detail the impact of such regulation on 5alpha-reductase activity, epithelial and stromal cell homogenates of human BPH were treated with phospholipases to specifically alter the structure of cellular phospholipid components. Phospholipase A(2) (PLA(2)) was used to alter the structure of the nonpolar, hydrophobic region of the membrane bilayer. Various types of phospholipase C (PLC) affect the polar, hydrophilic region of phospholipids. In epithelium and stroma, 5alpha-reductase activity was dose-dependently inhibited by PLA(2) and PLC type III. In epithelium and stroma, the mean IC(50) values of PLA(2) were 9.4 +/- 1.1 and 13.9 +/- 2.6 [U/mg protein +/- SEM], respectively. The mean IC(50) values of PLC type III in epithelium and stroma were 4.5 +/- 1.2 and 1.7 +/- 0.2 [U/mg protein +/- SEM], respectively. In epithelium as well as in stroma, 5alpha-reductase activity was more greatly inhibited by PLC type III than by PLA(2). Both in epithelium and stroma, PLA(2) significantly decreased the V(max) of 5alpha-reductase whereas its K(m) remained unaffected. A similar decrease in V(max) was found with PLC type III in epithelium and stroma. Furthermore, the K(m) of epithelial 5alpha-reductase increased significantly following the addition of PLC type III. The two phospholipases, with their specific substrate affinities and sites of hydrolysis, exhibited significantly different effects on 5alpha-reductase, indicating that 5alpha-reductase activity is not unspecifically affected by modification of the hydrophilic milieu. Rather, 5alpha-reductase activity is specifically modulated by various phospholipids and/or phospholipolysis mediated degradation products. These findings suggest that the structural composition of the lipid environment plays a fundamental role in the post-translational regulation of 5alpha-reductase activity in the epithelium and stroma of human BPH. Thus, changes in membrane phospholipid content seem to be instrumental in the expression of DHT-dependent processes.

Prognostic significance of low serum cholesterol after cardiothoracic surgery.

BACKGROUND: The precise prognostic significance of critically low cholesterol concentrations in patients undergoing cardiothoracic surgery is unknown. METHODS: In a retrospective case-control study, we analyzed the database of 2074 patients, of whom 87 died postoperatively in hospital. All patients underwent cardiothoracic surgery using a heart-lung machine. Age, sex, body mass index, preoperative ejection fraction, smoking, diabetes mellitus, type of operation, emergency surgery, renal deficiency, pulmonary hypertension, and endocarditis were considered together with serum concentrations of cholesterol, C-reactive protein, alanine aminotransferase, and triglycerides. The statistics included sensitivity, specificity, predictive value, odds ratio, and the ROC curve. RESULTS: Cholesterol decreased sharply immediately after surgery in both the deceased and the survivors. In the deceased, the mean cholesterol concentration (+/- SE) remained rather low between days 4 and 7 after surgery [2.46 +/- 0.16 mmol/L (95 +/- 6 mg/dL)]. In the survivors at that time, the mean cholesterol concentration was significantly (P <0.001) higher [4.37 +/- 0.03 mmol/L (169 +/- 1 mg/dL)]. The positive predictive value of a critically low cholesterol concentration [<3.10 mmol/L (<120 mg/dL)] was 25.4%, increasing to 66.6% at a cutoff value of 1.55 mmol/L (60 mg/dL). The odds ratio under those circumstances was 15.5, and the area under curve (C-statistic) was 0.90. CONCLUSIONS: The cholesterol concentration between days 4 and 7 after cardiothoracic surgery possesses a high prognostic significance in terms of in-hospital mortality.

3D norm data: the first step towards semiautomatic virtual craniofacial surgery.

When planning craniofacial surgical interventions, the ideal appearance of the patient is very important. The final appearance should be as close as possible to that which the patient would have if he/she were without defects. Our first step towards achieving this is to build a database containing sets of three-dimensional CT images that allows for comparison of the shape of a patient with defects to the typical shape of an age- and sex-matched "average" person without defects. We started to collect CT data from patients without pathologies and, in co-operation with two radiology institutes (in Mannheim and Heidelberg), over 100 CT data sets have now been collected and classified according to age and sex. It is necessary to choose an appropriate statistical method to calculate the norm data from the different data sets. Based on the statistical method, an age- and sex-matched "average" model of the anatomy will be created.

In vitro inhibition of androstenedione 5alpha-reduction by finasteride in epithelium and stroma of human benign prostatic hyperplasia.

Finasteride is a well known steroid 5alpha-reductase inhibitor. In this context, recently we have shown that in human benign prostatic hyperplasia (BPH) finasteride inhibits the 5alpha-reduction of testosterone to dihydrostestosterone (DHT) more effectively in the epithelium as compared to the stroma. The aim of the present study was to describe in epithelium and stroma of human BPH the effect of finasteride on the 5alpha-reduction of androstenedione, that is the second main circulating androgen in men, to androstanedione. Using a finasteride concentration of 75 nM and an androstenedione concentration of 220 nM, the mean inhibition [% +/- SEM] of 5alpha-reductase activity was significantly higher in epithelium (69 +/- 2) than in stroma (52 +/- 4). Both in epithelium and stroma, this inhibition of 5alpha-reductase activity was dose-dependent and competitive. Dixon plots as well as slope replots of Lineweaver-Burk plots showed that the mean inhibition constant Ki (nM +/- SEM) was significantly lower in epithelium (10 +/- 1 and 11 +/- 2, respectively) than in stroma (33 +/- 7 and 28 +/- 4, respectively) indicating a significantly stronger inhibitory effect of finasteride in epithelium. From those mean Ki values, it follows that in human BPH finasteride inhibits equally well both the 5alpha-reduction of androstenedione to androstanedione and testosterone to DHT. Based on these inhibition studies, there is no evidence for the coexistence of substrate-specific 5alpha-reductases converting either testosterone or androstenedione. However, the striking difference in finasteride sensitivity of the 5alpha-reduction between epithelium and stroma could be due to a cell-type specific expression of structurally different 5alpha-reductases as well as to a different access of finasteride to 5alpha-reductase in epithelium and stroma where, compared to each other, the lipid environment is significantly different.

Fatty acid composition of phospholipids in epithelium and stroma of human benign prostatic hyperplasia.

BACKGROUND: Although it is well known that prostatic 5alpha-reductase is active only in its membrane-bound form, rather limited information is available concerning the composition of cellular lipids in human BPH. Therefore, in the present study, the phospholipid fatty acid composition and content in epithelium and stroma of human BPH have been investigated for the first time. METHODS: Phospholipids separated on TLC plates were methylated and fatty acid methyl esters were analyzed by capillary gas chromatography. RESULTS: The fatty acid composition of total phospholipids was significantly different between epithelium and stroma. In particular, the percentage of oleic acid was significantly higher in epithelium as compared with stroma, whereas that of arachidonic acid was significantly lower in epithelium than in stroma. In addition, significant differences between epithelium and stroma were found in regard to the fatty acid composition of the main phospholipid subclasses. Another remarkable finding were the age-dependent changes of the fatty acid composition in human BPH. CONCLUSIONS: This study shows that the fatty acid composition of phospholipids is significantly different between epithelium and stroma of human BPH. Furthermore, age-dependent alterations of the fatty acid composition were found. Further studies are needed to determine whether the endogenous hormonal milieu in the prostate modulates the fatty acid composition of the prostatic cells, as well as what impact such modulation could have on the properties of membrane proteins, i.e., enzymes like the 5alpha-reductase and receptors, which are thought to be affected by alterations in membrane fluidity or composition, or both.

Kinetic analysis of androstenedione 5 alpha-reductase in epithelium and stroma of human prostate.

In the human prostate, various androgen-metabolizing enzymes are present. Among these enzymes, testosterone 5 alpha-reductase seems to be dominant. However, androstenedione is also a potential substrate of the prostatic 5 alpha-reductase. To address the question of to what extent the reduction of androstenedione to androstanedione occurs, the present study describes in detail the kinetic characteristics (Km and Vmax) and possible age-dependent alterations of this enzymatic step in epithelium and stroma of the human prostate. In normal prostate (NPR), the mean Km (nM) and Vmax (pmol/mg protein.h) were about twofold higher in stroma (Km, 211; Vmax, 130) than in epithelium (Km, 120; Vmax, 56), whereas in the benign prostatic hyperplasia (BPH), the mean Km (nM; mean +/- SEM) and Vmax (pmol/mg protein.h; mean +/- SEM) were about sixfold higher in stroma (Km, 668 +/- 121; Vmax, 415 +/- 73) than in epithelium (Km, 120 +/- 10; Vmax, 73 +/- 8). In BPH, those differences between epithelium and stroma were highly significant (p < 0.001). However, the efficiency ratios (Vmax/Km) of neither BPH nor NPR showed any significant differences between epithelium (NPR, 0.47; BPH, 0.62 +/- 0.06) and stroma (NPR, 0.70; BPH, 0.63 +/- 0.05). With respect to age-related changes, only stroma showed a significant increase of Km (p < 0.01) and Vmax (p < 0.05) with age. In summary, in both epithelium and stroma of the human prostate, a 5 alpha-reductase converts in measurable amounts androstenedione to androstanedione. The kinetic data were, in part, different between epithelium and stroma; the reason for this difference remains unclear. In comparison to other metabolic conversions, such as testosterone to dihydrotestosterone and androstenedione to testosterone, it is unlikely that, in the human prostate, the adrenal androgen androstenedione contributes significantly to the formation of testosterone and, further, of dihydrotestosterone.

Lipid composition in epithelium and stroma of human benign prostatic hyperplasia.

The lipid composition and concentration in human benign prostatic hyper-plasia (BPH) were investigated. The reason was to shed some light onto the lipid environment of cellular membranes, in which the epithelial and stromal 5 alpha-reductase of the human prostate have apparently to be embedded in order to gain an active state. The phospholipids were found to be the major portion (67% +/- 1.1) of total lipids in whole BPH homogenate, followed by cholesterol (29% +/- 1.1) and glyceride glycerols (4% +/- 0.9). In BPH epithelium, the lipid concentration related to wet weight and to protein was two to three-fold higher than in stroma. Assigning the lipid concentration on a per-cell basis (i.e., related to DNA), a significantly lower lipid concentration was found in the epithelium as compared to the stroma. In the stroma, a significantly higher phospholipid and lower cholesterol portion were found than in the epithelium. Moreover, sphingomyelin was found to comprise a higher portion in stromal than in epithelial phospholipids, whereas the percentage of phosphatidylserine was higher in the epithelial phospholipids. We discuss whether the significant differences in lipid concentration and composition between the epithelium and stroma of human BPH could have an impact on the activity of the membrane-bound 5 alpha-reductase, or whether such differences in the lipid environment are due to a different hormonal milieu in the epithelium and stroma of BPH.

[Benign prostatic hyperplasia--the outcome of age-induced alteration of androgen-estrogen balance?]. / Die benigne Prostatahyperplasie--das Ergebnis einer altersbedingten Entgleisung der Androgen-Estrogen-Balance?

Although human benign prostatic hyperplasia (BPH) is the most common tumor in men, its etiology is still unclear. At present, it is only widely accepted that BPH is under the endocrine control of the testes and strongly associated with aging. Therefore, in the human prostate we describe the impact of aging on the activity of various androgen metabolizing enzymes as well as on the endogenous androgen and estrogen levels. Moreover, the inhibition of 5 alpha-reductase by finasteride (Proscar) will be reported. Among all androgen metabolizing enzymes, within the human prostate 5 alpha-reductase is the most powerful one. Most of the androgen metabolizing enzymes undergo a significant age-dependent alteration. For distinct enzymes, the correlation with age is either negative (e.g. 5 alpha-reductase), or positive. Despite a complex pattern of age-dependent alterations, the dominance of 5 alpha-reductase among all androgen metabolizing enzymes is always maintained. This is underlined by a strong accordance between the age-dependent 5 alpha-reductase activity and the corresponding age-dependent endogenous DHT level. In epithelium, both the 5 alpha-reductase activity and the DHT level decrease with age, whereas in stroma not only the 5 alpha-reductase activity is rather constant over the whole age range but the DHT level as well. In contrast to the relatively unaltered DHT content in the stroma of the human prostate, the estrogen content follows an age-dependent increase. On the other side, in epithelium such a positive correlation between the estrogen level and age is not found. Thus, the age-dependent decrease of the DHT accumulation in epithelium and the concomitant increase of the estrogen accumulation in stroma will lead to a tremendous increase with age of the estrogen/androgen ratio in the human prostate. This could be of pathogenetic importance for BPH development if in fact a balanced androgen/estrogen synergism is necessary for the integrity of the normal human prostate. Finally, it is remarkable that the inhibition of 5 alpha-reductase activity by finasteride (Proscar) is significantly stronger in epithelium than in stroma. Therefore, it is conceivable that the global size-reduction of BPH under finasteride treatment is primarily due to the regression of BPH epithelium.

Enzyme activities in tissue of human benign prostatic hyperplasia after three months' treatment with the Sabal serrulata extract IDS 89 (Strogen) or placebo.

OBJECTIVE: The mechanism of action of plant extracts used for the medical treatment of human benign prostatic hyperplasia (BPH) is still unknown. In this prospective, randomized, double-blind trial, we investigated the possible influence of the Sabal serrulata extract IDS 89 (Strogen) on epithelial and stromal enzyme activities of BPH tissue. METHODS: 18 patients with BPH were randomly assigned to receive 3 x 2 capsules Strogen uno (320 mg/capsule) (n = 8) or placebo (n = 10) daily for 3 months. The activity (Vmax and Km) of 5 alpha-reductase. 3 alpha-HSORred, 3 beta-HSORred, and creatine kinase was determined in mechanically separated epithelium and stroma of human BPH. RESULTS: The multivariate correlation analysis revealed a positive correlation between therapy and the following enzyme alterations: (1) In epithelium, the substrate affinity of the 5 alpha-reductase decreased slightly (increase of Km value). (2) In stroma, the Vmax value of the 3 alpha-HSORred increased statistically distinctly, leading to a moderate increase of Vmax/Km. (3) In stroma, the Vmax value of the 3 beta-HSORred increased moderately, but not statistically significant. (4) In stroma, the Vmax value of creatine kinase increased significantly, leading to a statistically distinct increase of Vmax/Km. CONCLUSION: This double-blind, placebo-controlled clinical trial with the S. serrulata extract IDS 89 revealed significant biochemical changes at the cellular level of BPH tissue. However, the alterations are merely moderate, their biochemical causes and consequences regarding the pathophysiology of BPH rather uncertain. Therefore, more studies are needed before plant extracts like IDS 89 become valid candidates likewise synthetic substances already used for medical treatment of human BPH.

Effects of the sabal serrulata extract IDS 89 and its subfractions on 5 alpha-reductase activity in human benign prostatic hyperplasia.

Extract from fruit of Sabal serrulata are used in the treatment of human benign prostate hyperplasia (BPH). Therefore, it is of interest whether this phytopharmacon has any influence on the androgen metabolism in the human prostate. It was found that the extract IDS 89 of Sabal serrulata inhibited dose dependently 5 alpha-reductase activity in the epithelium and stroma of human BPH, the mean inhibition being 29% and 45%, respectively. This inhibitory effect is mainly due to the saponifiable subfraction of IDS 89 showing a mean 5 alpha-reductase inhibition of 39% and 38% in epithelium and stroma, respectively. The inhibition was dose dependent and noncompetitive. At a testosterone concentration of 580 nM as substrate for 5 alpha-reductase, the main fatty acids of the extract IDS 89 gave rise to a percentual enzyme inhibition in the epithelium and stroma as follows: 51% and 42% (lauric acid), 5% and 0% (oleic acid), 43% and 34% (myristic acid), 2% and 0% (palmitic acid), respectively. The inhibitory effect of lauric acid was noncompetitive and dose dependent up to a concentration of 0.2 nM, the maximal inhibition in the epithelium and stroma being 52% and 45%, respectively. The nonsaponifiable subfraction, consisting mainly of phytosterols, showed a mean inhibition of 5 alpha-reductase in the epithelium and stroma of 15% and 10%, respectively. Finally, the hydrophilic subfraction, containing carbohydrates, amino acids, and polysaccharides, showed no inhibitory effect. The present in vitro studies suggest that the Sabal serrulata extract IDS 89 has an inhibitory effect on 5 alpha-reductase in the epithelium and stroma of human BPH. This inhibition is mainly due to the fatty acids of the saponifiable subfraction.

Potential activities of androgen metabolizing enzymes in human prostate.

The entire androgen metabolism of the human prostate is an integral part of the DHT mediated cellular processes, which eventually give rise to the androgen responsiveness of the prostate. Therefore, the potential activities of various androgen metabolizing enzymes were studied. Moreover, the impact of aging on the androgen metabolism and the inhibition of 5 alpha-reductase by finasteride were studied. In epithelium (E) and stroma (S) of normal (NPR) and hyperplastic human prostate (BPH), for each enzyme being involved in the conversion either of testosterone via DHT, 3 alpha- and 3 beta-diol to the C19O3-triols or from testosterone to androstenedione and vice versa, the amount (Vmax) and Michaelis constant (Km) were determined by Lineweaver-Burk plots. Furthermore, Vmax/Km quotients were calculated, which served as an index for the potential enzyme activity. 17 enzymes showed a mean Vmax/Km > or = 0.10. The top four were the 5 alpha-reductases in E and S of NPR and BPH. Among those, the highest activity was found in E of NPR (1.6 +/- 0.2). Moreover, in E a significant age-dependent decrease of 5 alpha-reductase activity occurred, whereas in stroma rather constant activities were found over the whole age range. Similar age-dependent alterations were found for the cellular DHT levels. Finally, the finasteride inhibition of 5 alpha-reductase (IC50;nM) was stronger in E (35 +/- 17) than in S (126 +/- 15). In conclusion, 5 alpha-reductase is: (a) the outstanding androgen metabolizing enzyme in NPR and BPH; (b) dictating the DHT enrichment in the prostate; (c) under the impact of aging; and (d) preferentially inhibited by finasteride in E.

Protection of the chronic hypoxic immature rat heart during global ischemia.

The benefit of cardioplegic cardiac arrest for the protection of immature myocardium is controversial. We therefore investigated the efficacy of (1) topical hypothermia alone, (2) slow cooling by coronary perfusion hypothermia, and (3) cardioplegic cardiac arrest for the protection of isolated immature rats hearts (28 days) during 8 hours of global ischemia at 10 degrees C. The study was conducted in hearts from rats that were kept hypoxemic by lifelong exposure to simulated high altitude. Left ventricular function, endothelial function, the metabolic status, and the extent of myocardial injury were all assessed. Topical hypothermia provided superior protection in hypoxic hearts, with recovery of the maximum developed left ventricular pressure by 70.6% +/- 18.0% (mean +/- standard deviation) of its preischemic value (p < 0.01 versus slow cooling and versus cardioplegic protection). The same pattern of recovery was observed among control hearts. The degree of recovery of endothelial function after sole topical hypothermia measured 54% +/- 36% in hypoxic hearts and 62% +/- 37% in control hearts, but was not recordable in any of the other groups. Creatine kinase leakage and the myocardial high-energy content did not differ significantly among any of the groups. Rapid cooling by topical hypothermia alone provides superior protection in chronic hypoxic, immature rat hearts versus the protection conferred by slow cooling. St. Thomas' Hospital cardioplegic solution II does not afford additional protection. Endothelial injury caused by cold asanguineous perfusates, including cardioplegia, interferes with the recovery of vascular function, which, in turn, may limit mechanical function.

5 alpha-reductase inhibition by finasteride (Proscar) in epithelium and stroma of human benign prostatic hyperplasia.

Finasteride is a specific 5 alpha-reductase inhibitor that has been shown to reduce the size of human benign prostatic hyperplasia (BPH) by inhibiting the intraprostatic conversion of testosterone to 5 alpha-dihydrotestosterone. The aim of the present in vitro study was to describe in more detail the inhibitory effect of finasteride on 5 alpha-reductase in epithelium and stroma of human BPH. 5 alpha-Reductase activity in epithelium and stroma was inhibited dose-dependently by finasteride. The mean IC50 (50% inhibitory concentration) values, determined in the presence of various testosterone concentrations, were generally 2- to 4-fold lower in epithelium than in stroma. With finasteride concentrations greater than 5 nM, competitive inhibition of 5 alpha-reductase occurred both in epithelium and stroma. The mean inhibition constant Ki[nM +/- SEM] was 7 +/- 3 and 31 +/- 3 in epithelium and stroma, respectively. In the presence of finasteride concentrations < or = 5 nM, the epithelial 5 alpha-reductase seems to be inhibited in an uncompetitive manner, whereas such low finasteride concentrations cause either no inhibition (1-2 nM) or competitive inhibition (5 nM) in stroma. Our present study provides evidence that the inhibitory effect of finasteride on 5 alpha-reductase is much stronger in epithelium than in stroma. Therefore, it is conceivable that the global size-reduction of BPH under finasteride treatment is primarily due to the regression of BPH epithelium.

Effect of medium exchange rate on colony growth of the human tumor cell line MDA-231 cloned within the perfused capillary cloning system.

The conventional human tumor stem cell assay is limited by the lack of flexibility for drug scheduling with single agents and its inability to test drug combinations. Recently, we described the cloning of tumor cell lines within porous glass capillary tubes which allow free exchange of substances. The present study describes the influence of various perfusion modalities on the colony growth of the human tumor cell line MDA-231 cloned within the perfused capillary cloning system (PCCS). Colony growth of tumor cells within the PCCS is strongly dependent on perfusion tube volume, flow rate and duration of perfusion with growth medium. Best colony growth was achieved using a perfusion tube volume of 12 ml resulting in a cloning efficiency of 36.3%. Continuous perfusion with fresh medium did not improve the cloning efficiency; in fact, colony growth was hampered compared to colony growth within unperfused porous capillaries. However, cloning efficiency was acceptable when continuous perfusion was started at day 6 (26.4%) instead of day 0 (17.2%), or when a short perfusion with high volume (12 ml/h) was discontinued after 1 h at day 0. In contrast to the conventional capillary cloning system the PCCS has the potential for investigating secretion and kinetics of tumor-specific factors and the effect of growth-stimulating or growth-inhibiting drugs.

Distribution of immune effector cells within an experimental osteosarcoma of the nude rat.

In vivo studies on osteosarcoma are limited by the relative low incidence of this tumor in man. Therefore, there is a high dependence on a reliable experimental tumor model. In previous studies, a transplantable osteosarcoma of the athymic nude rat was established. In the present study the content and pattern of distribution of immune effector cells within this osteosarcoma were investigated by immunohistochemistry, and were related to histomorphologic findings. The absence of T-like cells within the tumor of 1- to 2-month-old athymic nude rats was shown using the T-lymphocyte-specific monoclonal antibody OX-19. In contrast, OX-6-positive cells, representing B lymphocytes and macrophages, were distributed throughout the whole tumor with a discrete accumulation at the borderline between the peripheral proliferative tumor tissue and the central necrotic area. Using the macrophage-specific monoclonal antibody ED1 we found the accumulation of mononuclear cells to consist mainly of macrophages. The distribution of these macrophages was closely related to histomorphologic tumor characteristics: the major proportion was found in the proliferative peripheral part of the tumor with highest macrophage content at the border to the central necrosis. As the measurement of tumor necrosis in osteosarcoma plays an important role in the judgement of therapeutic response, this distinct delimitation of tumor necrosis by macrophages could be helpful in the evaluation of therapeutic effects.(ABSTRACT TRUNCATED AT 250 WORDS)