Anecortave acetate for the treatment of subfoveal choroidal neovascularization secondary to age-related macular degeneration

PURPOSE

Anecortave acetate is a novel angiostatic cortisene being evaluated clinically for treatment of exudative age-related macular degeneration (ARMD). A randomized, placebo-controlled, efficacy and safety dose duration study of anecortave acetate for depot suspension (3 mg, 15 mg, 30 mg) in this patient population was completed in June 2003. As part of this trial, 128 patients with subfoveal choroidal neovascularization (CNV) secondary to ARMD were enrolled and treated for up to 2 years by 18 clinical sites in the United States and European Union.

METHODS

Study patients were evaluated clinically with detailed ophthalmic examinations, general physical examinations, assessments of best-corrected logMAR visual acuity, and angiographic evaluations. The Digital Angiography Reading Center (New York City, NY) assessed lesion eligibility while the clinical investigators assessed overall patient eligibility prior to treatment. As part of this study, study medication was delivered as a posterior juxtascleral depot using a specially designed curved cannula at 6-month intervals if in the masked investigator's opinion the patient's lesion could benefit from additional treatment.

RESULTS

The 2-year efficacy results of this placebo-controlled study demonstrated that RETAANE 15 mg (anecortave acetate for depot suspension) was statistically superior to placebo for stabilization of vision (<3 logMAR line change from baseline) and for inhibition of neovascular lesion growth. There were no serious treatment-related safety issues associated with either the study medication or the procedure for administration.

CONCLUSIONS

Anecortave acetate 15 mg for depot suspension is clinically efficacious compared to placebo for treatment of subfoveal exudative ARMD lesions when administered at 6-month intervals as a posterior juxtascleral depot.

Therapie der neovaskulären altersbedingten Makuladegeneration mit Ranibizumab/Lucentis™

Vascular endothelial growth factor (VEGF) is considered to play an essential role in the pathogenesis of age-related macular degeneration due to its vascular permeability-inducing and angiogenic properties. Ranibizumab, a small antibody fragment designed to competitively bind all VEGF isoforms, passes after intravitreal injection all retinal layers reaching the retinal pigment epithelium-choroid complex. Experimental animal models showed the drug to be safe and effective. Subsequently, Phase I/II clinical trials conducted in patients with neovascular AMD demonstrated a good safety profile, and a significant functional benefit. Ranibizumab therapy repeated every four weeks for the treatment of neovascular AMD is currently in Phase III clinical trials. Combination therapy trials aiming for improved treatment durability and effectiveness are currently ongoing as well as new treatment strategies using intermittent, optical coherence tomography (OCT) guided therapy. Anti-VEGF therapy using Ranibizumab is a promising new treatment option for neovascular AMD.

Expression angiogener Faktoren durch photodynamische Therapie

PURPOSE

The purpose of this study was to evaluate the impact of photodynamic therapy (PDT) on the regulation of angiogenic factors such as vascular endothelial growth factor (VEGF) and pigment epithelium derived factor (PEDF) in human eyes.

METHODS

Eyes of patients with untreatable malignancy served as the study eyes (n = 2), age-matched donor eyes were used as controls (n = 2). Standard Verteporfin-PDT was applied to intact areas of the posterior pole. One week after PDT the eyes were examined by ophthalmoscopy as well as fluorescein (FA) and indocyanine green angiography (ICGA). After enucleation the eyes were processed for LM/EM histology. Immunolabeling using specific antibodies against VEGF and PEDF was performed in PDT-treated areas, untreated collateral areas of study eyes and untreated areas of control eyes.

RESULTS

All PDT-treated areas demonstrated a typical choroidal hypofluorescence on FA/ICGA. In LM/EM histology a selective damage of choriocapillary endothelial cells was found. VEGF expression was localized only to choriocapillary endothelial cells and focally in larger choroidal vessels of PDT-treated areas. Untreated areas of study eyes and controls were VEGF-negative. PEDF staining was observed in retinas and RPE of all eyes, but only choroidal endothelial cells of PDT-treated areas showed a PEDF-positive reactivity.

CONCLUSION

PDT not only induces structural and angiographic, but also biological effects in human eyes. VEGF and PEDF expression can be documented in choroidal endothelial cells following PDT and could have an impact on the recovery process after treatment.

Photodynamic therapy with verteporfin: a new treatment in ophthalmology

Photodynamic therapy (PDT) with verteporfin is a new treatment modality in ophthalmology that has previously shown its effectiveness in treatment of a variety of neoplastic pathologies. In this therapeutic approach, the photosensitizer verteporfin is activated by non-thermal laser light to obtain closure of neovascular structures. Preclinical and clinical studies have indicated that PDT is a safe, selective, and effective treatment for choroidal neovascularization in age-related macular degeneration. No significant damage to the neurosensory retina was found, which explains why PDT does not cause loss of visual acuity and may be used in a larger population than laser photocoagulation. This review summarizes the mechanisms of action of PDT, and the results of preclinical and clinical studies in ophthalmology.

Dreidimensionale Darstellung photodynamischer Effekte und des Spontanverlaufs bei chorioidalen Neovaskularisationen

PURPOSE

Photodynamic therapy (PDT) induces occlusive and regenerative effects in choroidal neovascularization (CNV) and physiological choroid. The process of vascular alteration is documented quantitatively and qualitatively by three-dimensional angiography.

METHOD

In a prospective, randomized trial 30 patients with subfoveal CNV due to age-related macular degeneration (AMD) were treated with PDT or placebo. Fluorescence series with 32 tomographic images over a 4-mm depth were analyzed topographically and reproduced in a three-dimensional display.

RESULTS

At initial presentation CNV lesions were documented as a well-defined prominence in all patients. In the verteporfin group CNV height continuously decreased with each interval. In the placebo group CNV slightly increased in height during the first 6 months and remained stable at about 90% of the initial prominence at long-term follow-up. After 12 months 44% of the patients in the verteporfin group developed an additional choroidal defect.

CONCLUSION

Three-dimensional angiography offers a reliable documentation of CNV progression and regression during PDT. A decrease in CNV size is associated with an increase in choroidal perfusion defects.

[Photodynamic therapy for choroidal hemangioma. Long-term results]

AIM

Evaluation of functional and anatomical long-term results of patients with symptomatic choroidal hemangioma treated with photodynamic therapy (PDT).

PATIENTS AND METHODS

All 8 patients suffered from progressive loss of vision caused by exudation into the macular area. PDT with a verteporfin dose of 6 mg/m(2) body surface area and a light dose of 100 J/cm(2) at 692 nm was carried out. Two to four treatments were applied at 6 week intervals using a single laser spot. Standardized evaluation was used before and at 6-week intervals after each treatment and at 3, 6 and 12 months. In the further follow-up control intervals were extended up to 1 year in the case of stable anatomical and functional results.

RESULTS

All patients showed complete regression of the tumor. The tumor height was reduced from an average of 3.64 mm to undetectable. One patient showed a stable visual acuity, seven patients a significant increase. Central scotometry showed withdrawal of scotomas from the macula. No patient showed any sign of recurrence during the follow-up of up to 60 months.

CONCLUSION

The long-term results of patients with active choroidal hemangioma demonstrate that PDT is a most effective and safe treatment option. Complete tumor regression is combined with good functional recovery.

[Chorioretinal anastomosis as unfavourable prognostic factor during photodynamic therapy]

BACKGROUND

The aim of this study was the documentation of chorioretinal anastomosis in neovascular age-related macular degeneration (AMD) and correlation with functional and angiographic results following photodynamic therapy (PDT).

METHOD

A total of 100 patients presenting with neovascular AMD and indication for PDT based on the presence of predominantly classic choroidal neovascularization (CNV), underwent ophthalmoscopic and angiographic screening for chorioretinal anastomosis. Conventional PDT using verteporfin was performed according to the recommended standard procedure. The pre- and post-treatment status at 3 and 6 months post-PDT in all patients and at 1 week in selected patients was documented with respect to the central visual acuity test (ETDRS), ophthalmoscopy as well as fluorescein (FA) and indocyanine green angiography (ICGA).

RESULTS

A primary chorioretinal anastomosis was found in 6% ( n=12) of all eyes with CNV and classic PDT indication. Mean visual loss within the first 6 months after therapy was 3 lines indicating lack of visual stabilization according to the PDT study criteria.Furthermore, an increase in visual acuity could not be documented in any case. Angiography demonstrated continuous progression of CNV size although PDT had been uneventful. The characteristic initial occlusion of the CNV with homogeneous hypofluorescence was absent angiographically at 1 week post-PDT. The anastomosis was detected by ICGA in all eyes and by ophthalmoscopy or optical coherence tomography (OCT) in most eyes.

DISCUSSION

Chorioretinal anastomosis is not a rare finding associated with predominantly classic CNV. The presence of anastomosis appears to be an unfavourable prognostic factor during PDT. If a chorioretinal shunt is suspected evaluation by ICGA and/or OCT should be performed and the indication for PDT should be rediscussed.

Dose-related structural effects of photodynamic therapy on choroidal and retinal structures of human eyes

PURPOSE

To determine the effects of photodynamic therapy (PDT) on choroidal and retinal structures of human eyes.

METHODS

One eye from each of three patients with large malignant melanomas of the uvea destined for enucleation received PDT using verteporfin according to the approved treatment recommendations for patients with age-related macular degeneration. Two laser spots and two light doses (50 J/cm(2) and 100 J/cm(2)) were applied in unaffected chorioretinal areas. The effects of PDT were assessed by fluorescein and indocyanine-green angiography. The eyes were enucleated 1 week later, fixed in buffered paraformaldehyde/glutaraldehyde solution, bisected along the laser spots, and processed for light and electron microscopy.

RESULTS

In agreement with the clinical angiographic findings of hypofluorescence, a rather selective occlusion of the choriocapillary layer was observed in the 50-J/cm(2) PDT areas, whereas the 100-J/cm(2) PDT areas additionally revealed closure of deeper choroidal vessels and focal alterations of the retinal pigment epithelium. The overlying neurosensory retina, including photoreceptors and retinal capillaries, was well preserved in all PDT areas. Electron microscopy showed that alterations of the choriocapillary endothelium comprised swelling, shrinkage and fragmentation of endothelial cells, detachment from their basement membrane up to complete degeneration of the endothelial lining, leading to platelet aggregation, degranulation, and thrombus formation. Complete occlusion of capillary lumina by fibrin, thrombocytes, and cellular debris was observed. Remaining intact endothelial cells appeared to be reorganized into novel smaller vascular channels within occluded lumina.

CONCLUSIONS

PDT with verteporfin at a dosage used clinically induces selective occlusion of the physiological choriocapillaris without affecting deeper choroidal, retinal, and optic nerve vessels or the overlying retinal pigment epithelium and neurosensory retina. The main mechanism of action appears to be vascular thrombosis induced by cytotoxic damage of endothelial cells and platelet activation. An increase in light dose enhances the occlusive effect with thrombosis within deeper choroidal layers and damage to the retinal pigment epithelium. However, photoreceptors remained intact at all light doses used.

[Changes in neovascular membranes and normal choroid blood vessels after multiple photodynamic therapy treatments]

PURPOSE

ICG angiography (ICGA) was used to document the effect of repeated PDT (verteporfin) on size and leakage of choroidal neovascularisation in age-related macular degeneration (AMD) and treatment-related side effects on the choroid.

METHODS

Forty-two patients were followed over 24 months in a clinical trial for PDT in AMD. The ICGAs were performed every 3 months with a confocal laser scanning system. Patients received repeated verteporfin treatment. At each control visit, the patients were retreated if leakage was present in fluorescein angiography (FA).

RESULTS

A continuous, highly significant reduction in CNV size and leakage area was found over 24 months. The initial CNV size dropped by 23% from 3.86 mm2 to 2.98 mm2. The leakage area in the late phase of the angiogram decreased by 30.3% from 5.0 mm2 to 3.5 mm2. A significant side effect of PDT on the choroid was documented by an increased hypofluorescent area in ICGA. The maximum size of the hypofluorescent area was reached after 12 months. At month 24, the choroidal fluorescence showed recovery in respect to area and intensity of fluorescence. But hypofluorescence surrounding the CNV lesion was already present in 40 out of 42 eyes before treatment.

CONCLUSION

The ICGA confirms that repeated PDT treatments lead to a significant reduction in CNV size and leakage area over as long as 2 years. CNV lesions are surrounded by choriocapillary hypofluorescence in ICGA. PDT causes further hypoperfusion of the choroid but in the long-term significant recovery of choroidal perfusion was shown.

Separation of carvedilol enantiomers in very small volumes of human plasma by capillary electrophoresis with laser-induced fluorescence

A sensitive capillary electrophoretic method for the determination of carvedilol enantiomers in 100 microl of human plasma has been developed and validated. Carvedilol and the internal standard carazolol are isolated from plasma samples by liquid-liquid extraction using diethylether. A sensitive and selective detection is provided by helium-cadmium laser-induced fluorescence. The total analysis time is 17.5 min, about 30 min are needed for the sample preparation. The linearity of the assay ranges from 1.56 to 50 ng/ml per carvedilol enantiomer. The limits of quantification (LOQ) for the carvedilol enantiomers in 100 microl of human plasma are 1.56 ng/ml. The inter-day accuracy for R-carvedilol is between 95.8 and 103% (104% at LOQ) and for S-carvedilol between 97.1 and 103% (107% at LOQ); the inter-day precision values are between 3.81 and 8.64% (10.9% at LOQ) and between 5.47 and 7.86% (7.91% at LOQ) for R- and S-carvedilol, respectively. The small sample volume needed is especially advantageous for the application in clinical studies in pediatric patients. As an application of the assay concentration/time profiles of the carvedilol enantiomers in a 5-year-old patient receiving a test dose of 0.09 mg/kg carvedilol are reported.

[Choroidal changes after photodynamic therapy (PDT). A two-year follow-up study of 38 patients]

BACKGROUND

Photodynamic therapy is a new option for treatment of choroidal neovascularisation in patients with age-related macular degeneration. But choroidal changes and associated angiographic characteristics have not been further evaluated.

PATIENTS

Indocyanine green angiography was used to follow 38 patients with subfoveal choroidal neovascularisation in age-related macular degeneration over up to two years. All patients were treated with the photosensitizer Benzoporphyrin Derivative-MA receiving either a single or triple treatment.

RESULTS

Indocyanine green angiography shows two effects of photodynamic therapy. On the one hand a selective and lasting closure of choroidal neovascularisation was documented. Choroidal neovascularisation-size and leakage was significantly reduced in the entire treatment group to 20.7% and 28.3% one week after treatment, followed by a slow increase to 33.3% and 41.2% at up to two years longterm follow up. On the other hand photodynamic therapy causes typically a peri-lesional hypofluorescence in Indocyanine green angiography. This hypofluorescence is most likely due to choroidal hypoperfusion and vascular endothelial changes. A continuous increase in fluorescence was shown, reaching again 90% of the pretreatment intensity at 3 months, documenting a good recovery of the choroidal network.

CONCLUSION

The results show that photodynamic therapy is an alternative treatment in age-related macular degeneration with choroidal, subfoveal neovascularisation. Indocyaningreen angiography reflects well choroidal changes associated with this therapy and may be helpful to choose treatment intervals.

[Photodynamic therapy: ICG angiography findings]

PURPOSE

Photodynamic therapy (PDT) has been shown to provide immediate occlusion of choroidal neovascularization (CNV), followed by recurrent leakage after single PDT in the majority of the cases after 3 months. Indocyanine green angiography (ICG-A) was used to evaluate completeness of CNV occlusion, effects on physiological choroid and patterns of CNV recurrence.

METHODS

ICG-A was performed using a confocal laser scanning ophthalmoscope (HRA) before PDT at 1 week, 4 and 12 weeks following PDT. Twenty patients with single and 10 patients with repeated PDT treatments with administration of benzoporphyrin derivative and radiant exposures between 50 and 150 J/cm2 were evaluated.

RESULTS

Before PDT well-defined CNV was detectable during early ICG-A in all lesions. Depending on the number of treatments, CNV was absent in early phase ICG-A in 46-83%. CNV reappeared at week 4 in many and at 12 weeks in 77 (66%) of the cases. The treated area regularly showed hypofluorescence, which persisted until week 12. The intensity of choroidal hypofluorescence showed wide interindividual variability. Recurrence may originate from persistent feeder vessels.

CONCLUSION

With ICG-A we demonstrated that PDT induces hypofluorescence of CNV and choroid possibly due to perfusion changes or blockade phenomena. Recurrence may be due to reperfusion of the preexisting CNV or regrowth from feeder vessels.

[Effects of soft bedding on body perception and posture]

This investigation in several hospitals of the Federal Republic of Germany attempts for the first time to demonstrate the effects of soft bedding on the patients' condition on hand of well known and in other disciplines well established criteria. It could be shown that the softness of the mattress causes considerable problems for the patient. Furthermore, it becomes clear that the extent of nursing increases markedly with a very soft bedding of the patient in order to compensate for the disadvantages arising from it. Materials used in the prevention of bed sores (so called antidecubitus mattresses) have to be evaluated critically. Nurses must attempt to determine which kind of mattress ought to be used. If the mobility of the patient is not to be restricted even more, the use of a harder mattress may have to be considered.

Serine 752 in the cytoplasmic domain of the beta 3 integrin subunit is not required for alpha v beta 3 postreceptor signaling events

A naturally occurring point mutation (Ser752Pro substitution) in the beta subunit cytoplasmic domain of the platelet fibrinogen receptor GPIIb-IIIa (integrin alpha IIb beta 3), causing Glanzmann's thrombasthenia, has been shown to abrogate bidirectional transmembrane signaling of GPIIb-IIIa when expressed in heterologous cells (Chen YP, 1994, Blood 84, 1857-1865). As the vitronectin receptor alpha v beta 3 constitutively mediates cell attachment to RGD containing extracellular matrix proteins, the purpose of this study was to explore the regulatory role of Ser752 in alpha v beta 3 vitronectin receptor function, by cotransfecting recombinant human alpha v cDNA together with human beta 3 mutant cDNA into Chinese hamster ovary (CHO) cells. CHO cells expressing wild type human alpha v beta 3 acquired the ability to attach and spread on fibrinogen and von Willebrand factor, in contrast to non transfected CHO cells that only bound to vitronectin and fibronectin. Overexpression of a truncated recombinant beta 3 subunit (beta 3 delta 744) generated alpha v (hamster) beta 3 (human) chimers that mediated attachment but lost the ability to promote cell spreading on vitronectin, von Willebrand factor and fibrinogen, and to concentrate in focal contact sites, demonstrating a negative effect of beta 3 delta 744 on alpha v beta 3 dependent postreceptor occupancy events. Transfection of beta 3Ser752Pro reproduced the same negative effect as beta 3 delta 744, whereas beta 3Ser752Ala restored normal receptor function by allowing pronounced attachment and spreading on fibrinogen and von Willebrand factor. Our results provide evidence that (1) the C-terminal cytoplasmic domain of beta 3 (amino acids 744-762) is essential for alpha v beta 3 integrin postreceptor occupancy events; (2) within this domain, the Ser752Pro mutation affects alpha v beta 3 postreceptor occupancy events by preventing cell spreading and focal contact localization; (3) the defective receptor function of the vitronectin receptor alpha v beta 3 is due to the presence of Pro752, rather than the absence of Ser752, as a Ser to Ala substitution at position 752 restores normal beta 3 integrin cell spreading and adhesive plaque formation.

Phosphate-binding sites in phosphorylating glyceraldehyde-3-phosphate dehydrogenase from Bacillus stearothermophilus

The two anion-binding sites of the glycolytic glyceraldehyde-3-phosphate dehydrogenase (GraP-DH), the Ps and Pi sites, were originally proposed by Moras et al. [Moras, D., Olsen, K.W., Sabesan, M.N., Buehner, M., Ford, G.C. & Rossmann, M. G. (1975) J. Biol. Chem. 250, 9137-9162] to bind the C3 phosphate of the glyceraldehyde 3-phosphate and the inorganic phosphate respectively. Ps site mutants T179A, and T179M, and R231L, and the Pi site mutants T150A and T208 of the Bacillus stearothermophilus GraP-DH were constructed by site-directed mutagenesis and their kinetic properties were determined and compared with those of mutants R195L and R231G, already described [Corbier, C., Michels, S., Wonacott, A. & Branlant, G. (1994) Biochemistry 33, 3260-3265]. Taking advantage of the opportunity to study both the oxidoreduction and the phosphorylation step independently and the fact that the phosphorylation becomes rate determining for most of the mutants, the relative energetic contribution of each mutated amino acid to the phosphorylation step was evaluated. It was concluded that (a) Ps amino acids contribute more than the Pi amino acids to the stabilisation of the transition state relative to the ground state and (b) the side chain of arginine contributes more than that of the threonine residue. It was also concluded that the differences observed in the efficiency of the phosphorylation step for Ps and Pi mutants is a consequence of the orientation of the thioester bond of the thioacyl] intermediate relative to the attacking inorganic phosphate and not of a change in the intrinsic electrophilic property of the thioacyl intermediate. Furthermore, the kinetic results on the overall steps leading to the acyl-enzyme formation provided supplementary evidence that the C3 phosphate moiety of the glyceraldehyde 3-phosphate interacts with the Pi site during these steps and thus are consistent with the findings of Skarzynski et al. [Skarzynski, T., Moody, P. C. E. & Wonacott, A. J. (1987) J. Mol Biol. 193, 171-183] and Corbier et al. [Corbier, C., Michels, S., Wonacott, A. & Branlant, G. (1994) Biochemistry 33, 3260-3265] that recommended the reconsideration of the first definition of the Ps and Pi sites.

Characterization of the two anion-recognition sites of glyceraldehyde-3-phosphate dehydrogenase from Bacillus stearothermophilus by site-directed mutagenesis and chemical modification

The active site of the glycolytic glyceraldehyde-3-phosphate dehydrogenase (GAPDH) contains two anion recognition sites which have been attributed to the phosphate binding of the substrates, namely, glyceraldehyde 3-phosphate (Ps site) and inorganic phosphate (Pi site) [Moras et al. (1975) J. Biol. Chem. 250, 9137-9162]. In order to probe the role of both sites during the catalytic event, Arg 195 from the Pi site and Arg 231 from the Ps site of the Bacillus stearothermophilus enzyme have been changed to Leu and Gly, respectively, by site-directed mutagenesis. A comparative study of the chemical reactivity of the mutants and wild type toward 2,3-butanedione revealed a similarly high reactivity only for the R195L mutant and wild type, suggesting that only Arg 231 is chemically reactive toward 2,3-butanedione and that its reactivity is not influenced by the presence of the residue Arg 195, which is only 4 A distant. The kinetic consequences of the mutations were also analyzed for the consecutive steps in the forward catalytic reaction. The replacement of Arg 195 by Leu leads to a marked decrease of the rate of the first steps of the reaction which lead to the acylenzyme formation, in particular, the rate of enzyme-substrate association, while these steps occur at a similar or higher rate when Arg 231 is replaced by Gly. Furthermore, the mutations R195L and R231G also result in a 550-fold and 16,400-fold decrease in the second-order rate constant of phosphorolysis. This step becomes rate-determining for the R195L mutant.(ABSTRACT TRUNCATED AT 250 WORDS)

Arguments against a close relationship between non-phosphorylating and phosphorylating glyceraldehyde-3-phosphate dehydrogenases

Non-phosphorylating NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (EC 1.2.1.9) from spinach leaves was purified to homogeneity using an improved purification procedure. Thus, a major contaminant with molecular mass and ion-exchange properties similar to non-phosphorylating GAPDH was eliminated. Using this pure non-phosphorylating GAPDH, cofactor stereospecificity was determined by 1H NMR. Analysis of the NADPH formed from the hydride transfer from glyceraldehyde-3-phosphate to [4-2H]NADP showed that the enzyme belongs to the A-stereospecific dehydrogenase family. This stereospecificity is the same as that described for the aldehyde dehydrogenase (ALDH) superfamily and opposite to that of the phosphorylating GAPDH. Moreover, results from peptide sequencing analysis suggest a similarity in sequence between the non-phosphorylating GAPDH and ALDHs. Thus, the results taken all together strongly suggest that non-phosphorylating GAPDH belongs to the ALDH family and has no close relationship to the phosphorylating GAPDH class.

[Waste burdens--hazardous paths, aims of protection, environmental-toxicological assessment]

Contamination of soil by toxic substances, in particular from hazardous waste and air pollution, is not only an important environmental medical problem but also has far-reaching effects on the community. Environmental toxicological assessment is based on the different types of use taking the paths of ingestion into consideration. In the following article the scheme by Eikmann and Kloke systematizes this approach. Orientation values (soil values) for metals and several harmful organic substances for different types of use are presented.

[Determining guidelines for metals in children's playgrounds in North Rhine-Westphalia]

In 1990, the State of North-Rhine-Westphalia established an ordinance on the quality of playground soil and sand. This ordinance includes guideline values for toxic metals (arsenic, lead, cadmium, chromium) in playground soil not covered by vegetation and quality standards for sand to be applied on playgrounds. Additionally guideline values were set for mercury, nickel and thallium. The guideline values include two categories: guideline value I represents the upper limits (95-percentiles) of the background levels of toxic metals generally found in upper soil layers in the State of North-Rhine-Westphalia. Guideline values II ("action levels") were selected on the basis of toxicological considerations. In cases where concentrations of metals above these guideline values are detected, immediate actions (urgent redevelopment measures) are required. Quality standards for playground sand were established to ensure that only noncontaminated sand is applied for playgrounds.

Predictors of alcoholics' acquisition of treatment-related knowledge

Only modest relationships have been found between cognitive functioning and treatment outcome; there is some indication of better prediction of within-treatment progress. The current study attempted to determine whether either cognitive or sociodemographic/alcohol-related variables were predictive of learning in educational treatment. Eighty-seven male alcoholics were exposed to one hour of instruction on the medical effects of alcohol. Sociodemographic, alcohol-related, and cognitive functioning measures were obtained at the outset of treatment. Knowledge was assessed 24 hours prior to and 24 hours and three weeks after the intervention. Statistically significant increases in knowledge were found both 24 hours and three weeks following the educational intervention; retention of information declined significantly from 24 hours to three weeks post-intervention. Discriminant function analyses using either seven cognitive variables or six alcohol-related/sociodemographic variables significantly discriminated between learners and nonlearners 24 hours after the intervention. The weighted composite of measures in each of the analyses was able to successfully differentiate learners from nonlearners in over 70% of the cases. The findings suggest that the clinician may be able to employ a limited number of variables to differentiate between patients who will and will not be able to acquire knowledge from educational interventions.

Leu-7 in small cell neoplasms. An immunohistochemical study with ultrastructural correlations

In an effort to delineate the distribution of the Leu-7 antigen in small cell neoplasms, 283 paraffin-embedded examples of such tumors were studied immunohistochemically. These included 125 malignant lymphomas, 94 neuroendocrine carcinomas, 13 adenocarcinomas, 14 squamous carcinomas, four malignant melanomas, six neuroblastomas, four nephroblastomas (Wilms' tumors), six primitive neuroectodermal neoplasms, three "Askin" tumors, ten Ewing's sarcomas, and four embryonal rhabdomyosarcomas. Histologic diagnoses were verified by the use of electron microscopic study or independent immunostains. Overall, 44% of small cell neuroendocrine carcinomas expressed Leu-7, whereas nonendocrine carcinomas were uniformly nonreactive for this determinant. All neuroblastomas yielded immunopositivity, as did three primitive neuroectodermal tumors, three rhabdomyosarcomas, two "Askin" tumors, one nephroblastoma, one Ewing's sarcoma, and one malignant melanoma. None of the small cell lymphomas were Leu-7 positive. These results suggest that Leu-7 is a specific neuroendocrine marker in cases of small cell carcinoma, but its sensitivity is lower than that of other "endocrine" determinants. Reactivity patterns for Leu-7 in other small cell tumors demonstrate no specificity for any given line of cellular differentiation. However, the shared expression of this antigen by neuroblastomas, neuroectodermal tumors, Ewing's sarcomas, and Wilm's tumors contributes further to the hypothesis that these neoplasms may be related histogenetically.

Immunostaining for leukocyte common antigen using an amplified avidin-biotin-peroxidase complex method and paraffin sections. A study of 735 hematopoietic and nonhematopoietic human neoplasms

Antibodies to leukocyte common antigen (LCA) are valuable in surgical pathology in the diagnostic separation of malignant lymphomas from poorly differentiated neoplasms of other types. However, several publications have reported difficulty in obtaining adequate LCA labeling in paraffin-embedded specimens. To assess this problem further, we applied an amplified version of the avidin-biotin-peroxidase complex procedure to 315 formaldehyde-fixed hematopoietic malignancies, and 420 nonhematopoietic tumors that had been similarly processed. All non-Hodgkin's lymphomas were LCA-reactive with this method, whereas none of the nonhematopoietic neoplasms were stained. Twelve of 25 cases of Hodgkin's disease displayed LCA-positivity in Reed-Sternberg cells, but all contained reactive, benign inflammatory cells. Hence, the specificity of the amplified anti-LCA/avidin-biotin-peroxidase technique was 100%, and its sensitivity was 96%. This procedure should allow surgical pathologists to obtain reliable, reproducible staining of hematopoietic neoplasms in paraffin-embedded tissues.

[Toxic environmental factors in sudden infant death (SIDS)]

The increasing number of discussions on the influence of toxic environmental factors, including SIDS, prompted systematic postmortem chemical-toxicological investigations to be carried out on 54 SIDS cases and 2 control cases of the same age group. Tissue levels of arsenic, lead, cadmium, mercury, and pentachlorphenol, as well as other organic noxious agents, were measured in several organs. In addition, the COHb concentrations were determined. In spite of the widely scattered values, the extreme levels measured and the arithmetic means and median averages of As, Pb, Cd, Hg, PCP, and COHb had no more range in concentrations than can be expected for toxic effects - according to present knowledge anyway. It was observed that infants from an urban environment showed no greater concentration of noxious agents than did infants from rural regions. There were also no differences between SIDS cases and the controls, nor was there a correlation between infections of the respiratory system that are often morphologically detected - including laryngitis - and higher concentrations of these agents in the organs of SIDS cases.

Immunomodulating properties of the uremic pentapeptide H-Asp-Leu-Trp-Glu-Lys-OH in vitro

A pentapeptide originally isolated by Abiko and coworkers from the ultrafiltrate of a uremic patient was synthesized and studied for its in vitro effects on normal human peripheral blood mononuclear cells. The SRBC-rosette forming capacity of T cells was significantly reduced after preincubation of the cells with the peptide, whereas the viability and the percentage of SRBC-receptor positive cells as determined with a monoclonal antibody remained unchanged. The PHA and ConA induced proliferation of T cells as well as the induction of suppressor cells by ConA were decreased, while the proliferative responses to PWM and specific antigens were enhanced. MLC experiments with separated and reconstituted lymphocyte populations pointed to the T cell as the main target. The data presented demonstrate that at least some of the effects described for so-called middle molecules are reproducible with this peptide at concentrations eventually occurring in patients with chronic renal failure.