Prenatal diagnostic procedure for leukocyte adhesion deficiency

Leukocyte adhesion deficiency (LAD) is a rare autosomal recessive disorder which leads to recurrent severe infections due to impaired leukocyte functions. The disorder is caused by an absence or deficiency of leukocyte cell adhesion molecules (LeuCAMs) on the leukocyte membranes. The diagnosis is established with monoclonal antibodies against the LeuCAMs. We have carried out a prenatal diagnostic procedure by means of cordocentesis in a mother who was 20 weeks pregnant and had previously given birth to a child with LAD. This previous child had the severe form of LAD with undetectable mRNA for the β chain, the common subunit of the LeuCAMs. We found that the fetal granulocytes expressed the LeuCAMs normally. At birth, the baby was physically normal and showed no signs of impaired leukocyte functions.     

Normal ranges of the activities of ten different enzymes in 100 independent preparations of chorionic villi. Comparison of specimens from induced abortions,biopsies, and cultured cells

In order to obtain a large set of normal control values, the activities of three cytosolic enzymes of purine metabolism and seven lysosomal enzymes were determined in homogenates of chorionic villi derived from induced abortions of normal pregnancies (7th–12th week) in about 100 individual cases. Possible reasons for the rather wide ranges of normal distributions of enzyme activities are discussed. The values are compared: (1) with available data in the literature; (2) with activities determined in decidual homogenates prepared from the same samples; (3) with activities of cells of cultures established and grown from villi in the same samples; and (4) with enzyme activities measured in chorionic biopsies using the same methods. Implications for the prenatal diagnosis of the associated metabolic diseases are considered.     

Increased maternal serum alpha-fetoprotein and human chorionic gonadotropin in compromised pregnancies other than for neural tube defects or Down syndrome

Intrauterine fetal death occurred in four women who were ‘screen-positive’ in a screening programme for neural tube defects (NTDs) and Down syndrome (DS). These women had very high levels of maternal serum alpha-fetoprotein (MSAFP) and maternal serum human chorionic gonadotropin (MShCG). Therefore, we evaluated all ‘screen-positive’ women in whom both of these markers were ⩾ 2.0 multiples of the median. The cases fulfilling these criteria totalled 11, and only one of them had no complications. High concentrations of both MSAFP and MShCG in a number of these cases might have been caused by an increased placental volume, which, in turn, might have been induced by decreased perfusion of the placenta. We conclude that screening programmes wrongly determine a high risk of fetal NTD or DS if the concentrations of both these parameters are very high. Invasive diagnostic procedures should be avoided in these cases, particularly in view of the increased risk of an adverse pregnancy outcome.     

The influence of serum screening on the amniocentesis rate in women of advanced maternal age

We investigated the effect of maternal serum screening on the amniocentesis (AC) rate in women of advanced maternal age. The AC rate after maternal serum screening was compared in two groups of women with a singleton pregnancy, 855 women of 30–35 years and 98 of 36 years and older. In our population, 34·1 per cent of the women of 36 years or older were ‘screen-positive’ for Down syndrome. Only 41·2 per cent of these women chose to undergo AC as opposed to 88·2 per cent in the younger age group. Within the older age group, the tendency to avoid AC increased with increasing age. Maternal serum screening led to a significant decrease in the AC rate in the older women. In this group, a comparison between the ‘a priori’ and the calculated risk might have had more influence on the decision to undergo AC than being screen-positive or screen-negative as such. We conclude that maternal serum screening had a major effect on the AC rate in women of advanced maternal age. This is of importance in a society in which the average maternal age is steadily increasing.     

Biochemical composition of Nyctiphanes australis and its possible use as an aquaculture feed source: Lipids,pigments and fluoride content

Nyctiphanes australis contained, on a dry weight basis, an average of 52% crude protein and 5.0 to 9.5% lipid. The fatty acid profile of N. australis was markedly unsaturated, with a mean total 3 fatty acid content of 48.6±2.4% of total fatty acids. N. australis contained high levels of the essential long-chain polyunsaturated fatty acids eicosapentaenoic (EPA, 20:53) and docosahexaencic (DHA, 22:63), ranging from 16.6 to 36.5% and 11.1 to 24.8%, respectively. The concentration of total carotenoids ranged from 137 to 302 g g^–1 dry wt, with no significant differences in concentrations found with season or life stage. The carotenoids were comprised of 79.5% astaxanthin and 20.5% canthaxanthin. The lipid and pigment compositions of N. australis suggest that the species could serve as a suitable feed source for cultured salmonids. Like other euphausiids, N. australis contained high levels of fluoride, with a seasonal range between 277 and 3507 g g^–1 dry wt. The high fluoride levels found in N. australis would not detract from its potential as a feed source for salmonids because ingested fluoride is largely absorbed by the skeleton.     

Introduction of the northern Pacific asteroid Asterias amurensis to Tasmania: reproduction and current distribution

The northern Pacific asteroid Asterias amurensis (Lütken) has been recently introduced to Tasmania and is now well-established in east and southeast Tasmania. This sea star is conspicuous throughout the Derwent River estuary and is particularly abundant in the Hobart port area. Reproduction of two populations of A. amurensis at Sullivans Cove and at Sandy Bay was investigated from August 1993 to October 1994 by gonadal histology and measurement of the gonad index (GI). An intense period of vitellogenic and spermatogenic growth started in April, with the breeding condition reached by June. In 1994, peak GI was recorded at Sullivans Cove in July and at Sandy Bay in August. Although these data indicated that the Sullivans Cove population spawned before the Sandy Bay population, histological examination revealed that major spawning activity occurred in both populations from July onwards. In the early part of the breeding season, gametogenesis proceeded in parallel with spawning, with released gametes being replaced by continual gametogenesis. Maintenance of a higher GI during the early part of the breeding season at Sandy Bay was due to prolonged gametogenic replacement at this site. Spawning continued to October 1994, resulting in a sharp decline in the GI. The cyclic expansion and regression of the genital haemal sinus coincident with germinal proliferation and growth, respectively, support the contention that haemal fluid provides nutrients for gametogenesis. In Tasmania, A. amurensis experiences temperature and photoperiod regimes similar to those experienced by endemic populations of this species in the north Pacific. Comparison of reproduction of A. amurensis in Japan and Tasmania at similar latitudes shows that gametogenesis of the northern and southern populations is 6 mo out of phase. This phase shift provides evidence for photoperiodic regulation of gametogenesis in A. amurensis. The similar trend in sea-temperature regimes associated with the stages of gametogenesis in northern and southern populations suggests that temperature also plays a modulatory role. Based on the periodicity of reproduction and the ontogeny of A. amurensis, the planktotrophic larvae of this species would be expected to be in the plankton for several months from the end of winter through summer. Considering the highly fecund, dispersive life-history of A. amurensis, the southeast Tasmanian populations have considerable potential to serve as a seed source for establishment of new populations of this asteroid elsewhere in Tasmania and in mainland Australia. Received: 18 October 1996 / Accepted: 22 October 1996     

Bestimmung von Nitrodiphenylaminen und verwandten Verbindungen im Sickerwasser einer Rüstungsaltlast

Goal, Scope and Background

Nitrodiphenylamines can be found at abandoned military sites where the explosive 2,2′,4,4′,6,6′-hexanitrodiphenylamine (hexyl) or diphenylamine as a stabilizer of smokeless powder was handled. Aim of the present study is the development of HPLC methods for the analysis of contaminants which can be expected in particular under aerobic conditions at premises which are contaminated by nitrodiphenyl-amines and related compounds.

Methods

A list of 13 compounds which can be expected at these explosives factories was deduced from literature studies. HPLC methods were developed for the analytes. Water samples from the unsaturated zone of a former hexyl-producing factory were collected by suction cups and the material was analysed according to these procedures to demonstrate the practicability of the new methods and to verify the existence of the postulated compounds in the environment of the former nitration plant.

Results and Conclusion

The new HPLC methods are suitable for the exploration of sites contaminated by nitrodiphenylamines. Beside some hexyl its intermediates 1-chloro-2,4-dinitrobenzene, 2,4-dinitrodiphenylamine und 2,2′,4,4′-tetranitrodiphenylamine were identified in the leachate water.

Recommendation and Perspective

It is advisable to include at least these 4 compounds in the examination of former hexyl-producing plants. Several unknown peaks were observed in the HPLC-chromatogram. It is recommendable to perform further investigations of the unidentified compounds to compile a final list of analytes for military sites polluted by nitrodiphenylamines.     

A rule-based screening environmental risk assessment tool derived from EUSES

Within the context and scope of the forthcoming European Union chemical regulations (REACH), there is a need to be able to prioritise the chemicals for evaluation. Therefore, a simple, pragmatic and adequately conservative approach for the identification of substances of very low or no immediate concern at an early stage is presented. The fundamental principles and basic concepts are derived from the EU Technical Guidance Document and EUSES, and are translated into an easy-to-use rule-based system. For this development, the effect on risk characterisation ratios (RCRs) of the key environmental parameters in EUSES was quantified (taking into account several standardised chemical release scenarios). Using statistical analysis, ranges were identified for each key parameter, within which the end result of the assessment was not significantly affected. This information was then translated into a lookup table from which environmental risk characterisation ratios can be directly read as a function of a few parameters.     

Effect of oxygen and salt on haemolymph oxygen binding in the brine shrimp Artemia franciscana

The oxygen-binding properties of haemolymph from laboratory-reared Artemia franciscana were investigated in vitro. Adult female brine shrimp without eggs were acclimated to seven different combinations of salinity and oxygen. The oxygen affinity (P₅₀) of unprocessed haemolymph rises with acclimation oxygen partial pressure (PO₂) up to normoxic values, after which no influence of oxygen occurs. The increase in P₅₀ with acclimation PO₂ can be explained by the change in proportion of each of three different haemoglobins in the haemolymph. Salinity acclimation has no effect on haemolymph P₅₀. The effects of the different major salts [NaNO₃, NaCl, Ca(NO₃)₂, Mg(NO₃)₂], pH, and the metal-binding ligand EGTA on the oxygen-binding properties of buffered haemolymph (of shrimp acclimated to 10 salinity) were also studied. Little or no effect of these salts could be found. A small Bohr effect (pH 6.5 to 9.1, =-0.11) was noted. Addition of EGTA caused a significant decrease of the oxygen affinity at concentrations up to 50 mmoll^-1.