Phytotoxicity assessment of diclofenac and its phototransformation products

The occurrence of pharmaceuticals in the environment is an emerging issue. Several studies observed that the non-steroidal anti-inflammatory drug diclofenac is ubiquitously present in most of the surveyed surface waters, worldwide. Phototransformation of diclofenac was reported from laboratory assays as well as in natural water systems, raising the question of possible adverse effects of the phototransformation products of diclofenac to aquatic organisms. In this study the phytotoxicity of diclofenac exposed to natural sunlight was evaluated using synchronized cultures of the unicellular chlorophyte Scenedesmus vacuolatus. Diclofenac dissolved in ultra-pure water at 50 mg L(-1) was exposed to natural midsummer sunlight for a maximum of 145 h. Twice a day subsamples were taken for chromatography and parallel phytotoxicity assessment. Inhibition of algal reproduction of the initial diclofenac solution was in the mg L(-1) range indicating no specific toxicity of diclofenac towards S. vacuolatus. Fast degradation of diclofenac was observed with half lives between 3.3 and 6.4 h during the first and the third day of exposure, respectively. Phytotoxicity increased after 3.5 h of exposure of diclofenac to sunlight and showed a maximum of sixfold enhanced toxicity after 53 h of exposure to sunlight. Several phototransformation products were found during the experiment. The time courses of the relative concentration of three transformation products significantly correlated with enhanced phytotoxicity during the experiment. This indicates a high toxicity potential of phototransformation products of diclofenac at concentration levels that may come close to environmental concentrations of residual diclofenac after degradation. We conclude that toxicity assessment of phototransformation products should be included in the risk assessment of pharmaceuticals in the environment.

A prospective, randomized, double-blind, placebo-controlled multi-centre study on the efficacy and safety of sublingual immunotherapy (SLIT) in children with seasonal allergic rhinoconjunctivitis to grass pollen

BACKGROUND

Especially in childhood, sublingual immunotherapy (SLIT) could offer advantages over subcutaneous therapy. However, limited data on its efficacy is available.

METHODS

In four German centres 97 children (age 3-14 years) with allergic rhinoconjunctivitis to grass pollen were enrolled in a prospective, double-blind trial comparing SLIT (Pangramin SLIT; ALK-SCHERAX, 0.5 microg major allergens, three times per week, 32 months) with placebo. Primary endpoint was a multiple symptom-medication score for changes in seasonal diary entries between the first and third year of the study (SLIT n=39; placebo n=38).

RESULTS

The multiple symptom-medication score was significantly reduced by SLIT to 77.3% of the placebo group (P=0.0498). The subsequent analysis of the single endpoints did not reveal significant differences for symptom scores in favour of SLIT (85.1% of placebo group; P=0.22). However, the medication score improved significantly (67.1% of placebo group; P=0.0025). Furthermore, secondary endpoints assessing in vivo immune responses did not differ significantly between the groups. However, retrospective analysis showed some inhomogeneity for clinical and in vitro parameters at the beginning of the study. Allergic side effects with possible relation to the study drug were reported in both groups (SLIT 49%, placebo 27%, P=0.026).

CONCLUSION

Our study indicates that SLIT had a positive effect on the reduction of a multiple symptom-medication score, mainly by significantly reducing rescue medication use, but had no significant effect on symptoms alone in children with rhinoconjunctivitis to grass pollen compared with a placebo.

Degradation of the drug diclofenac in water by sonolysis in presence of catalysts

Diclofenac, as one of the most popular antiphlogistics, is produced in great quantities. Nowadays this drug is ubiquitously present in the aquatic environment due to its resistance to biodegradation. Degradation by ultrasonic irradiation is a possibility to eliminate diclofenac from water without the addition of chemicals. The sonolysis of diclofenac in water was investigated at ultrasound frequencies of 24 kHz, 216 kHz, 617 kHz, and 850 kHz and in the presence of various catalysts (TiO2, SiO2, SnO2, and titanosilicate). The degradation of diclofenac by sonolysis of an aqueous solution at 617 kHz followed first-order kinetics. Catalysts, especially TiO2 increased the rate of degradation. Within 30 min of irradiation, the relative concentration of diclofenac decreased from 100% to 16%. By HPLC and GC-MS methods, chlorinated anilines, phenols and carboxylic acid derivatives were detected as a result of the sonolysis. About 35% of organic chlorine was transformed into inorganic chloride. Most of the identified degradation products in the sonolysis of diclofenac were the same compounds that were detected during photo-oxidation experiments with this anti-inflammatory drug.

Dicarba analogues of α-conotoxin RgIA. Structure, stability, and activity at potential pain targets

α-Conotoxin RgIA is both an antagonist of the α9α10 nicotinic acetylcholine receptor (nAChR) subtype and an inhibitor of high-voltage-activated N-type calcium channel currents. RgIA has therapeutic potential for the treatment of pain, but reduction of the disulfide bond framework under physiological conditions represents a potential liability for clinical applications. We synthesized four RgIA analogues that replaced native disulfide pairs with nonreducible dicarba bridges. Solution structures were determined by NMR, activity assessed against biological targets, and stability evaluated in human serum. [3,12]-Dicarba analogues retained inhibition of ACh-evoked currents at α9α10 nAChRs but not N-type calcium channel currents, whereas [2,8]-dicarba analogues displayed the opposite pattern of selectivity. The [2,8]-dicarba RgIA analogues were effective in HEK293 cells stably expressing human Cav2.2 channels and transfected with human GABAB receptors. The analogues also exhibited improved serum stability over the native peptide. These selectively acting dicarba analogues may represent mechanistic probes to explore analgesia-related biological receptors.

Unrestricted principal components analysis of brain electrical activity: issues of data dimensionality, artifact, and utility

Principal components analysis (PCA) was performed on the 1536 spectral and 2944 evoked potential (EP) variables generated by neurophysiologic paradigms including flash VER, click AER, and eyes open and closed spectral EEG from 202 healthy subjects aged 30 to 80. In each case data dimensionality of 1500 to 3000 was substantially reduced using PCA by magnitudes of 20 to over 200. Just 20 PCA factors accounted for 70% to 85% of the variance. Visual inspection of the topographic distribution of factor loading scores revealed complex loadings across multiple data dimensions (time-space and frequency-space). Forty-two non-artifactual factors were successful in classifying age, gender, and a separate group of 60 demented patients by linear discriminant analysis. Discrimination of age and gender primarily involved EP derived factors, whereas dementia primarily involved EEG derived factors. Thirty-eight artifactual factors were identified which, alone, could not discriminate age but were relatively successful in discriminating gender and dementia. The need to parsimoniously develop real neurophysiologic measures and to objectively exclude artifact are discussed. Unrestricted PCA is suggested as a step in this direction.

Reference values for cardiac troponins T and I in healthy neonates

OBJECTIVES

Cardiac troponins T (cTnT) and I (cTnI) are the most sensitive biochemical parameters in the detection of myocardial damage. In neonates, in utero exposure to tocolytic therapy results in detectable values of cardiac troponins after delivery. Additionally, some preliminary results suggest that the upper reference limits for healthy newborns are higher than those for adults but definitive reference limits for newborns are not available. Our objective was to determine those limits.

DESIGN AND METHODS

In this study we investigated the distribution of cTnT and cTnI in cord blood of 869 healthy newborns. cTnT was determined with the 3rd generation assay and cTnI with the Dade Behring assay on a Dimension RxL. For data analysis Student's t test and the Mann-Whitney U test were used.

RESULTS

Using the 99th percentile, the upper reference limit in healthy termed newborns was 0.097 microg/l for cTnT and 0.183 microg/l for cTnI. Compared to the adult values, the newborn upper limit was tripled for cTnT and doubled for cTnI. Statistically significant differences were found between males and females for cTnT and between natural childbirth and caesarean section for cTnI.

CONCLUSION

Healthy-termed newborns have a higher upper reference limit for both cTnT and cTnI compared to adults. This circumstance must be taken into account when interpreting slightly "elevated" cTnT and cTnI values in newborns.

Predictive value of inflammatory and coagulation parameters in the course of severe ulcerative colitis

Alterations in markers of coagulation have been found in patients with inflammatory bowel disease. Our aim was to study the predictive value of coagulation and inflammatory parameters in the course of severe ulcerative colitis. Twenty-seven patients were included. The disease course was followed for one year. Sensitivity, specificity, negative predictive value, positive predictive value, and likelihood ratio, as well as the clinical predictive value of laboratory variables were calculated. Inflammatory variables, such as ESR, CRP, and leukocyte and platelet count showed poor diagnostic accuracy. Several coagulation parameters, such as fibrinogen and fibrin(ogen) degradation products, were increased in patients with active ulcerative colitis, whereas coagulation factor XIII was decreased. No significant relationship between clinical course and coagulation parameters was demonstrated, though both inflammatory and coagulation parameters were useful in the assessment of disease activity in patients with active ulcerative colitis.

Quantified neurophysiology with mapping: statistical inference, exploratory and confirmatory data analysis

Topographic mapping of brain electrical activity has become a commonly used method in the clinical as well as research laboratory. To enhance analytic power and accuracy, mapping applications often involve statistical paradigms for the detection of abnormality or difference. Because mapping studies involve many measurements and variables, the appearance of a large data dimensionality may be created. If abnormality is sought by statistical mapping procedures and if the many variables are uncorrelated, certain positive findings could be attributable to chance. To protect against this undesirable possibility we advocate the replication of initial findings on independent data sets. Statistical difference attributable to chance will not replicate, whereas real difference will reproduce. Clinical studies must, therefore, provide for repeat measurements and research studies must involve analysis of second populations. Furthermore, Principal Components Analysis can be employed to demonstrate that variables derived from mapping studies are highly intercorrelated and data dimensionality substantially less than the total number of variables initially created. This reduces the likelihood of capitalization on chance. The need to constrain alpha levels is not necessary when dimensionality is low and/or a second data set is available. When only one data set is available in research applications, techniques such as the Bonferroni correction, the "leave-one-out" method, and Descriptive Data Analysis (DDA) are available. These techniques are discussed, clinical and research examples are given, and differences between Exploratory (EDA) and Confirmatory Data Analysis (EDA) are reviewed.

Solar radiation influence on the decomposition process of diclofenac in surface waters

Diclofenac can be detected in surface water of many rivers with human impacts worldwide. The observed decrease of the diclofenac concentration in waters and the formation of its photochemical transformation products under the impact of natural irradiation during one to 16 days are explained in this article. In semi-natural laboratory tests and in a field experiment it could be shown, that sunlight stimulates the decomposition of diclofenac in surface waters. During one day intensive solar radiation in middle European summer diclofenac decomposes in the surface layer of the water (0 to 5 cm) up to 83%, determined in laboratory exposition experiments. After two weeks in a field experiment, the diclofenac was not detectable anymore in the water surface layer (limit of quantification: 5 ng/L). At a water depth of 50 cm, within two weeks 96% of the initial concentration was degraded, while in 100 cm depth 2/3 of the initial diclofenac concentration remained. With the decomposition, stable and meta-stable photolysis products were formed and observed by UV detection. Beyond that the chemical structure of these products were determined. Three transformation products, that were not described in the literature so far, were identified and quantified with GC-MS.

Safety and Efficacy of Dose-Intensive Oral Vitamin A in Subjects with Sun-Damaged Skin

PURPOSE

Previously, we reported the results of a Phase III, placebo-controlled trial in 2297 randomized participants with moderately severe actinic keratoses wherein 25000 IU/day vitamin A caused a 32% risk reduction in squamous cell skin cancers. We hypothesized that dose escalation of vitamin A to 50000 or 75000 IU/day would be both safe and more efficacious in skin cancer chemoprevention.

EXPERIMENTAL DESIGN

One hundred and twenty-nine participants with severely sun-damaged skin on their lateral forearms were randomized to receive placebo or 25000, 50000, or 75000 IU/day vitamin A for 12 months. The primary study end points were the clinical and laboratory safety of vitamin A, and the secondary end points included quantitative, karyometric image analysis and assessment of retinoid and rexinoid receptors in sun-damaged skin.

RESULTS

There were no significant differences in expected clinical and laboratory toxicities between the groups of participants randomized to placebo, 25000 IU/day, 50000 IU/day, and 75000 IU/day. Karyometric features were computed from the basal cell layer of skin biopsies, and a total of 22600 nuclei from 113 participants were examined, showing statistically significant, dose-response effects for vitamin A at the 25000 and 50000 IU/day doses. These karyometric changes correlated with increases in retinoic acid receptor alpha, retinoic acid receptor beta, and retinoid X receptor alpha at the 50000 IU/day vitamin A dose.

CONCLUSIONS

The vitamin A doses of 50000 and 75000 IU/day for 1 year proved safe and equally more efficacious than the 25000 IU/day dose and can be recommended for future skin cancer chemoprevention studies.

AKAP5 complex facilitates purinergic modulation of vascular L-type Ca2+ channel CaV1.2

The L-type Ca2+ channel CaV1.2 is essential for arterial myocyte excitability, gene expression and contraction. Elevations in extracellular glucose (hyperglycemia) potentiate vascular L-type Ca2+ channel via PKA, but the underlying mechanisms are unclear. Here, we find that cAMP synthesis in response to elevated glucose and the selective P2Y11 agonist NF546 is blocked by disruption of A-kinase anchoring protein 5 (AKAP5) function in arterial myocytes. Glucose and NF546-induced potentiation of L-type Ca2+ channels, vasoconstriction and decreased blood flow are prevented in AKAP5 null arterial myocytes/arteries. These responses are nucleated via the AKAP5-dependent clustering of P2Y11/ P2Y11-like receptors, AC5, PKA and CaV1.2 into nanocomplexes at the plasma membrane of human and mouse arterial myocytes. Hence, data reveal an AKAP5 signaling module that regulates L-type Ca2+ channel activity and vascular reactivity upon elevated glucose. This AKAP5-anchored nanocomplex may contribute to vascular complications during diabetic hyperglycemia.

Enriching the captive elephant population genetic pool through artificial insemination with frozen-thawed semen collected in the wild

The first successful AI in an elephant was reported in 1998, using fresh semen. Since then almost 40 calves have been produced through AI in both Asian and African elephants worldwide. Following these successes, with the objective of enriching the captive population with genetic material from the wild, we evaluated the possibility of using frozen-thawed semen collected from wild bulls for AI in captivity. Semen, collected from a 36-yr-old wild African savanna elephant (Loxodonta africana) in South Africa was frozen using the directional freezing technique. This frozen-thawed semen was used for four inseminations over two consecutive days, two before and two after ovulation, in a 26-yr-old female African savanna elephant in Austria. Insemination dose of 1200 × 10(6) cells per AI with 61% motility resulted in pregnancy, which was confirmed through ultrasound examination 75, 110 and 141 days after the AI procedure. This represents the first successful AI using wild bull frozen-thawed semen in elephants. The incorporation of AI with frozen-thawed semen into the assisted reproduction toolbox opens the way to preserve and transport semen between distant individuals in captivity or, as was done in this study, between wild and captive populations, without the need to transport stressed or potentially disease-carrying animals or to remove animals from the wild. In addition, cryopreserved spermatozoa, in combination with AI, are useful methods to extend the reproductive lifespan of individuals beyond their biological lifespan and an important tool for genetic diversity management and phenotype selection in these endangered mammals.

Tacrolimus vs. cyclosporine immunosuppression: results in advanced-stage disease compared with historical controls treated exclusively with cyclosporine

A phase HI comparative trial of tacrolimus- vs. cyclosporine-based graft-vs.-host disease (GVHD) prophylaxis for human leukocyte antigen (HLA)-identical sibling bone marrow transplantation showed less GVHD but poorer survival in the tacrolimus arm. To test the comparability of the two treatment arms with respect to baseline survival prognosis, a matched control study using exclusively cyclosporine-treated patients from the International Bone Marrow Transplant Registry (IBMTR) database was performed. Controls were matched (2:1) based on age (within 5 years), disease, and pretransplant disease status. Two-year survival for tacrolimus-treated clinical trial patients was similar to that of their cyclosporine-treated matched controls (27 and 24%, respectively), and 2-year survival of the cyclosporine-treated clinical trial patients was similar to that of their cyclosporine-treated matched IBMTR controls (42 and 45%, respectively). Consistent with the clinical trial results, the cyclosporine-treated IBMTR controls matched to the tacrolimus group had significantly poorer 2-year survival than the cyclosporine-treated IBMTR controls matched to the cyclosporine group (24 and 45%, respectively; p < 0.01). No significant difference was seen in GVHD between the cyclosporine-treated clinical trial patients and their matched controls; however, the tacrolimus-treated clinical trial patients had significantly less GVHD than their cyclosporine-treated IBMTR controls (p < 0.01). These results support the hypothesis that the survival difference in the phase III trial resulted from an imbalance in the underlying risk factors for death in the two groups rather than from the randomized immunosuppressive regimen.

The environmental fate of the antiviral drug oseltamivir carboxylate in different waters

Since the efficacy of oseltamivir carboxylate (OC) as the active metabolite of Tamiflu has been demonstrated against influenza viruses and even against the avian influenza virus (H5N1), millions of Tamiflu treatment courses are stockpiled worldwide. This was done not at least to follow the recommendations of the World Health Organization (WHO) to cope with a viral influenza pandemic. Concentrations up to 26-32 microg l(-1) OC in river catchment areas in the United States and in the United Kingdom had been predicted recently for a pandemic case, assuming an apparent persistence of the Tamiflu metabolite. Such concentrations may involve the risk of generation of antiviral resistance. But there is still a lack of data concerning the stability of OC in a surface water environment. Under this aspect these predictions have to be validated with concrete facts about the environmental fate of OC. In this article we summarized the results of three different daylight exposure experiments with OC in different waters under sterile and non-sterile conditions simulating shallow water processes at the latitude of approximately 52 degrees N. Using a river water solution containing 50 microg l(-1) OC under non-sterile conditions a half-life time of 17.8 days was observed. Direct photolysis plays no or only a negligible role for the decomposition of OC. Degradation of OC seems to occur as a combination of microbial metabolism and indirect photolysis.

The ICP-dependency of resistance to cerebrospinal fluid outflow: a new mathematical method for CSF-parameter calculation in a model with H-TX rats

The international The simultaneous measurement of the resistance and compliance during a single investigation minimizes the patients exertion. In contrast to the classical method it is not necessary that the ICP reaches a plateau. Our mathematical method diverges with t he description of a pressure dependent slope of the function for the resistance from the static examination models. We proved our mathematical method by the use of a dynamic infusion test in 10 H-Tx rats without hydrocephalus and five hydrocephalic H-Tx rats. For that we are able to take the non linearity of the CSF resorption into consideration.

The importance of the intrathecal infusion test in the diagnostic of normal-pressure hydrocephalus

OBJECTIVE

The intrathecal infusion test is a reliable method for diagnosing normal-pressure hydrocephalus (NPH).

METHODS

Between May 1982 and January 1997, we investigated 200 patients suspected of having NPH by carrying out an intrathecal infusion test with a constant-flow technique. The resistance to cerebrospinal fluid outflow in the intrathecal infusion test was the main criterion for grouping patients into those with NPH or those with cerebral atrophy. A further differentiation into early stage and advanced stage was made by measuring the compliance, this being the secondary criterion.

RESULTS

In 107 patients (54%), the diagnosis of NPH could be confirmed. Of these, 102 patients (95%) underwent a shunt operation. Graduation of NPH and cerebral atrophy following the results of the infusion test at an early stage and an advanced stage allows prognostic evaluations about the course of disease to be made. Patients with NPH at an early stage reported an improvement of their symptoms in the follow-up after a shunt operation in 65% of cases, while 50% of those with advanced-stage NPH reported improvement.

CONCLUSION

The computer- aided infusion test allows a reliable differentiation between patients with NPH and those with cerebral atrophy.

Feasibility of using administrative data to compare hospital performance in the EU

OBJECTIVE

To describe hospitals' organizational arrangements relevant to the abstraction of administrative data, to report on the completeness of administrative data collected and to assess associations between organizational arrangements and completeness of data submission.

DESIGN

A cross-sectional

STUDY DESIGN

utilizing administrative data.

SETTING AND PARTICIPANTS

Randomly selected hospitals from seven European countries (The Czech Republic, France, Germany, Poland, Portugal, Spain, and Turkey).

MAIN OUTCOME MEASURES

Completeness of data submission for four quality indicators: mortality after acute myocardial infarction, stroke and hip fractures and complications after normal delivery.

RESULTS

In general, hospitals were able to produce data on the four indicators required for this research study. A substantial proportion had missing data on one or more data items. The proportion of hospitals that was able to produce more detailed indicators of relevance for quality monitoring and improvement was low and ranged from 40.1% for thrombolysis performed on patients with acute ischemic stroke to 63.8% for hip-fracture operations performed within 48 h after admission for patients aged 65 or older. National factors were strong predictors of data completeness on the studied indicators.

CONCLUSIONS

At present, hospital administrative databases do not seem to be an appropriate source of information for comparison of hospital performance across the countries of the EU. However, given that this is a dynamic field, changes to administrative databases may make this possible in the near future. Such changes could be accelerated by an in-depth comparative analysis of the issues of using administrative data for comparisons of hospital performances in EU countries.

Naturally acquired antibodies to Bacillus anthracis protective antigen in vultures of southern Africa

Sera from 19 wild caught vultures in northern Namibia and 15 (12 wild caught and three captive bred but with minimal histories) in North West Province, South Africa, were examined by an enzyme-linked immunosorbent assay (ELISA) for antibodies to the Bacillus anthracis toxin protective antigen (PA). As assessed from the baseline established with a control group of ten captive reared vultures with well-documented histories, elevated titres were found in 12 of the 19 (63%) wild caught Namibian birds as compared with none of the 15 South African ones. There was a highly significant difference between the Namibian group as a whole and the other groups (P < 0.001) and no significant difference between the South African and control groups (P > 0.05). Numbers in the Namibian group were too small to determine any significances in species-, sex- or age-related differences within the raw data showing elevated titres in four out of six Cape Vultures, Gyps coprotheres, six out of ten White-backed Vultures, Gyps africanus, and one out of three Lappet-faced Vultures, Aegypius tracheliotus, or in five of six males versus three of seven females, and ten of 15 adults versus one of four juveniles. The results are in line with the available data on the incidence of anthrax in northern Namibia and South Africa and the likely contact of the vultures tested with anthrax carcasses. It is not known whether elevated titre indicates infection per se in vultures or absorption of incompletely digested epitopes of the toxin or both. The results are discussed in relation to distances travelled by vultures as determined by new tracking techniques, how serology can reveal anthrax activity in an area and the issue of the role of vultures in transmission of anthrax.

Quantitative mikrospektrographische Messungen zur Aufnahme von Thionin durch lebende Zellen von Allium Cepa

Die Aufnahme des basischen Thiazinfarbstoffs Thionin wird quantitativ in Abhängigkeit von cH, Außenkonzentration und Färbezeit untersucht. Durch Vergleich mit den für den basischen Farbstoff Acridinorange bereits veröffentlichten Messungen wird wahrscheinlich gemacht, daß es erforderlich ist, innerhalb der Gruppe der basischen Farbstoffe Differenzierungen hinsichtlich der Bedingungen ihrer Aufnahme in lebende Zellen zu treffen. Die Farbstoffe Thionin (Thio) und Acridinorange (AO) ähneln sich in ihrem physikalischen Verhalten außerordentlich, auch in ihren Dissoziationskonstanten für die erste Protonenanlagerung besteht kein großer Unterschied. Während jedoch beim AO das Speicherungsmaximum in den Vakuolen lebender Zellen schon mehrere pH-Einheiten unterhalb des pK erreicht wird, folgt die Aufnahme des Thionins streng der Dissoziationskurve. Diese Unterschiede werden in der Tatsache begründet gesehen, daß Acridinorange-Moleküle analog zum Methylenblau (MB) in wäßriger Lösung nicht existent sind, sondern lediglich die undissoziierten Basenmoleküle [AO]+OH- und [MB]+OH-. Beim Thionin dagegen treten neben den [Thio]+OH--Molekülen [Thio]-MoIeküle auf.

Tissue-specific adrenergic regulation of the L-type Ca2+ channel CaV1.2

Ca²⁺ influx through the L-type Ca²⁺ channel Cav1.2 triggers each heartbeat. The fight-or-flight response induces the release of the stress response hormone norepinephrine to stimulate β-adrenergic receptors, cAMP production, and protein kinase A activity to augment Ca²⁺ influx through Ca_v1.2 and, consequently, cardiomyocyte contractility. Emerging evidence shows that Ca_v1.2 is regulated by different mechanisms in cardiomyocytes compared to neurons and vascular smooth muscle cells.

The importance of the intrathecal infusion test in the diagnosis of normal pressure hydrocephalus

The intrathecal infusion test is a reliable method in diagnosing normal pressure hydrocephalus. Between May 1982 and January 2000 we investigated 300 patients suspected of having normal pressure hydrocephalus (NPH) by carrying out an intrathecal infusion test in a constant flow technique. The resistance to cerebrospinal fluid outflow (R(out)) in the intrathecal infusion test was the main criterion of grouping patients into those with normal pressure hydrocephalus or those with cerebral atrophy. A further differentiation into early stage and late stage was made by measuring the compliance (C(p)) - this being the secondary criterion. In 162 patients (54%) the diagnosis of NPH could be confirmed. Of these, 154 patients (95%) underwent a shunt operation. Graduation of NPH and cerebral atrophy following the results of the infusion test at an early stage and an advanced stage allow the conclusion of prognostic evaluations about the course of disease to be made. Patients with NPH in an early stage report in the follow up an improvement of their symptoms after a shunt operation in 65 percent of cases, and those with advanced stage NPH, in 50 percent of cases. The computer aided infusion test allows a reliable differentiation between patients with NPH and those with cerebral atrophy.