[Recognising and reporting child abuse by orthodontists]

In 2013, the child abuse and domestic violence reporting code was introduced in the Netherlands, which obliged caregivers to report suspicions of child abuse or domestic violence. In 2014, a survey was conducted among dentists on this subject. However, nothing was known about the use of the reporting code among orthodontists. In December 2015, a survey was sent to members of the Dutch Orthodontic Society (NVvO). The survey consisted of 20 items about applying the reporting code and experiences with patients. Most orthodontists were aware of the reporting code (83%) and had implemented this in their practice (64%). Nevertheless, orthodontists found it difficult to recognise signs of child abuse, mostly because of a lack of experience in this area. Most orthodontists who suspected child abuse took action, mainly by seeking advice from the foundation 'Veilig Thuis' ('Safe at Home').

Cancer-Related Stigma in South Africa: Exploring Beliefs and Experiences Among Cancer Patients and the General Public

Background: Stigma refers to a distinctive, discrediting characteristic, rendering its bearer tainted or inferior by others. Definitions of stigma acknowledge the recognition of difference; and devaluation. Evidence, largely from high-income countries suggests that cancer is a stigmatized disease. Cancer-related stigma is not well-documented in South Africa, and little is known about how it impacts health-seeking behavior, treatment adherence, quality of life and psychosocial well-being in cancer patients. Limited research has explored perceptions and cultural representations of cancer but an in-depth focus on this is lacking. This context-specific information is essential for relevant, effective intervention. Aim: This study aims to increase understanding of cancer-related stigma in South Africa and the role of cultural beliefs in contributing to this. Findings will be used to inform a larger study and ultimately, interventions to address cancer-related stigma in communities in which the Cancer Association of South Africa (CANSA) is working. Methods: This qualitative study was conducted in two provinces of South Africa, KwaZulu Natal and the Western Cape and included participants from a range of cultural and racial groups. Cancer patients over 18 years were recruited through CANSA's Service Delivery teams to participate in focus groups or one to one in depth interviews. Six focus groups and 40 in depth interviews were conducted with cancer patients. Data collection focused on understanding patient experiences of cancer stigma; cognitive, emotional and behavioral responses to this; and inputs on interventions to address this. Six focus groups were also conducted with noncancer patients recruited from local communities to explore cultural perceptions of cancer and reasons for stigmatization. Audio recordings were transcribed and translated; coded using NVivo 11; and analyzed by the authors using thematic analysis. Results: Results indicated very poor knowledge of cancer both in patients and nonpatients. Overwhelmingly, findings highlight the perception of cancer as a “death sentence”, influencing patients' experiences and responses of others in numerous ways. The influence of cultural beliefs was relevant, exacerbating stigma in some cases. The location of the cancer also played a role in determining level of stigmatization. Certain body parts (associated with masculine and feminine roles) as well as more visible cancers/side-effects were more stigmatised. Conclusion: Results indicate that stigmatization is a significant factor for cancer patients in South Africa, increasing social isolation and negatively impacting quality of life. The implications of the findings for intervention development will be discussed. Education is needed but requires a different focus for different cultural groups.

Diagnosis of acute puerperal metritis by electronic nose device analysis of vaginal discharge in dairy cows

The objective of this study was to estimate the diagnostic accuracy of an electronic nose device using vaginal discharge samples to diagnose acute puerperal metritis (APM) in dairy cows. Uterine fluid was sampled manually with a gloved hand and under sterile conditions for electronic nose device analysis (day in milk (DIM) 2, 5, and 10) and bacteriologic examination (DIM 5), respectively, and on additional days, if APM was diagnosed during the daily clinical examinations. A dataset containing samples from 70 cows was used to create a model and to validate the APM status predicted by this model, respectively. Half of the dataset (n = 35; 14 healthy and 21 metritic cows) was provided with information regarding the APM diagnosis and contained all three measurements (DIM 2, 5, and 10) for each cow and was used as a training set whereas the second half was blinded (n = 35; 14 healthy and 21 metritic cows) and contained only the samples collected on DIM 5 of each cow and was used to validate the created prediction model. A receiver operating characteristic curve was calculated using the prediction results of the validation test. The best observed sensitivity was 100% with specificity of 91.6% when using a threshold value of 0.3. The calculated P-value for the receiver operating characteristic curve was less than 0.01. Overall, Escherichia coli was isolated in eight of 28 (28.6%) and 22 of 42 (52.4%) samples collected from healthy and metritic cows, respectively. Trueperella pyogenes and Fusobacterium necrophorum were isolated in 14 and six of 28 (50.0% and 21.4%) and 17 and 16 of 42 (40.5% and 38.1%) samples collected from healthy and metritic cows, respectively. The prevalence of Escherichia coli and Trueperella pyogenes was similar in the samples obtained from metritic cows used for the training set and the validation test. The results are promising especially because of the objective nature of the measurements obtained by the electronic nose device.

Technical note: Evaluation of odor from vaginal discharge of cows in the first 10 days after calving by olfactory cognition and an electronic device

The objective of this study was to determine test characteristics (i.e., intra- and interobserver variability, intraassay variability, sensitivity, and specificity) of an evaluation of odor from vaginal discharge (VD) of cows in the first 10 d postpartum conducted by olfactory cognition and an electronic device, respectively. In experiment 1, 16 investigators (9 veterinary students and 7 licensed veterinarians) evaluated 5 VD samples each on 10 different days. The kappa test revealed an agreement between investigators (interobserver) of κ=0.43 with a Fleiss adjusted standard error of 0.0061. The overall agreement was the same for students (κ=0.28) and veterinarians (κ=0.28). Mean agreement within observers (intraobserver) was κ=0.52 for all observers, and 0.49 and 0.62 for students and veterinarians, respectively. In experiment 2, the repeatability of an electronic device (DiagNose; C-it, Zutphen, the Netherlands) was tested. Therefore, 5 samples of VD from 5 cows were evaluated 10 times each. The repeatability was 0.97, determined by Cronbach's α. In experiment 3, 20 samples collected from healthy cows and 20 of cows with acute puerperal metritis were evaluated by the 16 investigators and the DiagNose using a dichotomous scale (1=cow with acute puerperal metritis; 0=healthy cow). Sensitivity and specificity of olfactory evaluation was 75.0 and 60.1% compared with 92.0 and 100%, respectively, for the electronic nose device. The study revealed a considerable subjectivity of the human nose concerning the classification into healthy and sick animals based on the assessment of vaginal discharge. The repeatability of the electronic nose was higher. In conclusion, the DiagNose system, although imperfect, is a reasonable tool to improve odor assessment of VD. The current system, however, is not suitable as a screening tool in the field. Further research is warranted to adapt such electronic devices to practical on-farm screening tools.

Social integration of people with intellectual disability: insights from a social psychological research programme

BACKGROUND

Social integration of people with intellectual disability (ID) moving into regular neighbourhoods tends to be studied and evaluated without detailed knowledge about the social psychological aspects of everyday interaction between neighbours with and without ID. The goal of the present paper is to show how the authors' social psychological research programme may contribute to this field of inquiry.

METHODS

The different ways in which societies respond to features and behaviours that may be perceived as deviant are theoretically analysed. Results of empirical studies are reported to clarify how social responses to people with ID are special in terms of perceptions, emotions and interaction desires of people with and without ID during a pre-contact and contact phase.

RESULTS

On the basis of the theoretical analysis, it is concluded that regular neighbouring in modern Western society often takes the form of benevolent tolerance, rather than stigmatisation and prejudice. However, empirical studies reveal that, prior to getting people with ID as new neighbours, prospective neighbours without ID experience a specific pattern of emotions that are associated with specific desires (e.g. with respect to information supply or a caring relationship). These anticipatory reactions are dependent on the expected size of the group moving in and on the severity of ID. Furthermore, while actually engaging in neighbouring, neighbours with and without ID appear to have experiences related to behaviour of residents, staff and features of housing facilities that are perceived as (in)congruent with regular neighbouring.

CONCLUSIONS

It is concluded that interpersonal relationships between neighbours with and without ID should not be simplified in terms of attitudes that would be primarily prejudiced/stigmatising versus entirely accepting. Rather, our studies paint a more complex picture of sometimes ambivalent thoughts, feelings and interaction needs that all should be taken into account to make social integration a success.

[Orthodontics and quality of life]

The impact of oral health on quality of life among orthodontic patients was assessed using the Child Oral Health Impact Profile. Responses of parents and children to questions about the quality of life of the child were very similar, suggesting that the parents were quite well able to assess the oral health-related quality of life of their children. Girls experienced more adverse effects on their quality of life due to oral health problems as compared to boys. Subscales of the Child Oral Health Impact Profile appeared to have little predictive value with respect to the general feeling of healthiness among orthodontic patients.

Perceptions of Dutch orthodontic patients and their parents on oral health-related quality of life

OBJECTIVE

To test the hypotheses that 1) there is no difference between orthodontic patients' and their parents' reports of patients' oral health-related quality of life, and 2) there are no gender differences.

MATERIALS AND METHODS

The sample consisted of 182 orthodontic patients (age range, 8-15) and their parents. Respondents were required to complete the Child Oral Health Impact Profile (COHIP). Items were divided into five different subscales, and scores on all subscales were compared between and within groups. Also, scores on six additional items regarding treatment expectations and global health perception were compared. Two hypotheses were tested: first, that no differences between parents and patients would be detected, and second, that no differences between boys and girls would be found.

RESULTS

The first hypothesis could not be rejected. Only a few minor differences between parents and patients were found. The second hypothesis was rejected. Differences between boys and girls were found on the subscales Emotional Well-Being and Peer Interaction, indicating that girls experience more effects of oral health on their quality of life than do boys.

CONCLUSIONS

Parents' reports on their children's oral health-related qualities of life were in agreement with reports of the orthodontic patients. This suggests that parents are suitable alternatives to their children in surveys measuring oral health-related quality of life.

[Attitudes towards orthodontic treatment. A comparison of treated and untreated adolescents]

Dutch adolescents' attitudes towards orthodontic treatment and the determinants of these attitudes are unknown. The aim of the present study was to evaluate treated and untreated adolescents' attitudes towards orthodontic treatment, and to examine possible determinants of these attitudes. Previously treated adolescents were found to have a more positive attitude towards orthodontic treatment than untreated adolescents. Age, but not gender, was found to be a significant predictor for their general attitude towards orthodontic treatment. Consequently, it was concluded that attitudes were not determined by one specific aspect, but by a combination of several determinants.

Lower body positive pressure by anti-G garment inflation: a suitable method to increase pulmonary capillary wedge pressure in healthy elderly subjects

In a study on non-invasive assessment of pulmonary capillary wedge pressure (PCWP), we sought a method to increase PCWP non-invasively. We hypothesized that inflation of an anti-G garment was suitable to increase PCWP non-invasively in healthy elderly subjects. In 20 subjects, aged 70 +/- 4 years (mean +/- SD), before, immediately after, and 4 min after anti-G garment inflation to 52 mmHg, PCWP and mean pulmonary artery pressure (MPAP) were measured with a Swan-Ganz catheter, and mean arterial blood pressure (MAP) with Finapres, in supine and semi-recumbent position. Supine, PCWP (mmHg, mean +/- SD) increased from 9.9 +/- 2.1 to 15.5 +/- 3.9** immediately after inflation and 13.4 +/- 3.7** at 4 min; semi-recumbent from 8.9 +/- 2.0 to 17.5 +/- 3.3** and 14.7 +/- 2.9** (*P<0.05, **P< 0.001 versus before inflation). MPAP (mmHg) increased after inflation: supine 16.9 +/- 2.3 to 22.3 +/- 4.6** and 20.6 +/- 3.9** and semi-recumbent 15.7 +/- 2.8 to 24.3 +/- 5.1** and 22.5 +/- 3.5**, suggesting that increased preload was the primary effect of anti-G garment inflation. Supine MAP (mmHg) increased from 96.0 +/- 11.3 to 101.4 +/- 13.4** and 100.5 +/- 12.7* and semi-recumbent from 102.0 +/- 8.9 to 108.3 +/- 11.4** and 106.0 +/- 11.3*, suggesting an effect of increased afterload as well. The latter was supported by an increase in total peripheral resistance (d s cm(-5)) from 1346 +/- 299 to 1441 +/- 384 after 4 min (P = 0.057) and from 1461 +/- 341 to 1532 +/- 406 (P = 0.054), supine and semi-recumbent respectively, while cardiac output remained unchanged. Complications did not occur. We conclude that in healthy elderly subjects, anti-G garment inflation is a safe, non-invasive, method to induce a significant increase in PCWP. Our findings justify its application in future studies in which non-invasive temporary increase in PCWP is required.

Mode of antimicrobial action of vanillin against Escherichia coli, Lactobacillus plantarum and Listeria innocua

AIMS

To investigate the mode of action of vanillin, the principle flavour component of vanilla, with regard to its antimicrobial activity against Escherichia coli, Lactobacillus plantarum and Listeria innocua.

METHODS AND RESULTS

In laboratory media, MICs of 15, 75 and 35 mmol l(-1) vanillin were established for E. coli, Lact. plantarum and L. innocua, respectively. The observed inhibition was found to be bacteriostatic. Exposure to 10-40 mmol l(-1) vanillin inhibited respiration of E. coli and L. innocua. Addition of 50-70 mmol l(-1) vanillin to bacterial cell suspensions of the three organisms led to an increase in the uptake of the nucleic acid stain propidium iodide; however a significant proportion of cells still remained unstained indicating their cytoplasmic membranes were largely intact. Exposure to 50 mmol l(-1) vanillin completely dissipated potassium ion gradients in cultures of Lact. plantarum within 40 min, while partial potassium gradients remained in cultures of E. coli and L. innocua. Furthermore, the addition of 100 mmol l(-1) vanillin to cultures of Lact. plantarum resulted in the loss of pH homeostasis. However, intracellular ATP pools were largely unaffected in E. coli and L. innocua cultures upon exposure to 50 mmol l(-1) vanillin, while ATP production was stimulated in Lact. plantarum cultures. In contrast to the more potent activity of carvacrol, a well studied phenolic flavour compound, the extent of membrane damage caused by vanillin is less severe.

CONCLUSIONS

Vanillin is primarily a membrane-active compound, resulting in the dissipation of ion gradients and the inhibition of respiration, the extent to which is species-specific. These effects initially do not halt the production of ATP.

SIGNIFICANCE AND IMPACT OF THE STUDY

Understanding the mode of action of natural antimicrobials may facilitate their application as natural food preservatives, particularly for their potential use in preservation systems employing multiple hurdles.

Mass-producible and wireless wide-area networks of electronic noses: problems and solutions

This paper focuses on the development of a wide-area network of wireless electronic noses and the solutions found to the problems encountered, both of a technical nature and the management involved when employing large amounts of field units. Examples of field test results are given, to illustrate the abilities of such a system.

Cost analysis of PAPNET-assisted vs. conventional Pap smear evaluation in primary screening of cervical smears

OBJECTIVE

To assess the difference in costs between PAPNET-assisted and conventional microscopy of cervical smears when used as a primary screening tool.

STUDY DESIGN

We performed time measurements of the initial screening of smears by four cytotechnologists in one laboratory. Time was measured in 816 conventionally screened smears and in 614 smears with PAPNET-assisted screening. Data were collected on the components of initial screening, clerical activities and other activities in the total work time of cytotechnologists in the routine situation and on resource requirements for both techniques.

RESULTS

PAPNET saved an average of 22% on initial screening time per smear. Due to costs of processing and additional equipment, the costs of PAPNET-assisted screening were estimated to be $2.85 (and at least $1.79) higher per smear than conventional microscopy. The difference in costs is sensitive to the rate of time saving, the possibility of saving on quality control procedures and the component of the initial screening time in the total work time of cytotechnologists.

CONCLUSION

Although PAPNET is time saving as compared with conventional microscopy, the associated reduction in personnel costs is outweighed by the costs of scanning the slides and additional equipment. This conclusion holds under a variety of assumptions. Using PAPNET instead of conventional microscopy as a primary screening tool will make cervical cancer screening less cost-effective unless the costs of PAPNET are considerably reduced and its sensitivity and/or specificity are considerably improved.

Cloning of sucrose:sucrose 1-fructosyltransferase from onion and synthesis of structurally defined fructan molecules from sucrose

Sucrose (Suc):Suc 1-fructosyltransferase (1-SST) is the key enzyme in plant fructan biosynthesis, since it catalyzes de novo fructan synthesis from Suc. We have cloned 1-SST from onion (Allium cepa) by screening a cDNA library using acid invertase from tulip (Tulipa gesneriana) as a probe. Expression assays in tobacco (Nicotiana plumbaginifolia) protoplasts showed the formation of 1-kestose from Suc. In addition, an onion acid invertase clone was isolated from the same cDNA library. Protein extracts of tobacco protoplasts transformed with this clone showed extensive Suc-hydrolyzing activity. Conditions that induced fructan accumulation in onion leaves also induced 1-SST mRNA accumulation, whereas the acid invertase mRNA level decreased. Structurally different fructan molecules could be produced from Suc by a combined incubation of protein extract of protoplasts transformed with 1-SST and protein extract of protoplasts transformed with either the onion fructan:fructan 6G-fructosyltransferase or the barley Suc:fructan 6-fructosyltransferase.

27Al nuclear magnetic resonance study of synthetic and natural corundum (alpha-Al2O3). Some experimental aspects of quantitative 27Al nuclear magnetic resonance spectroscopy

The 27Al nuclear magnetic resonance (NMR) response of a series of natural and synthetic corundum (alpha-Al2O3) samples is studied quantitatively by short-pulse excitation and frequency-stepped adiabatic half-passage (FSAHP). Using on- and off-resonance nutation NMR, it was established that the quadrupole coupling parameters of visible Al is identical in all samples. Remarkably, the relaxation behavior for the aluminum is very different in the various samples and has a marked effect on the quantitative response. In natural corundum samples the 27Al spin-lattice relaxation is very efficient as these samples contain paramagnetic impurities. As a result, however, the full signal could not be recovered, which is attributed to relaxation broadening of spins in the vicinity of these impurities. In synthetic samples, containing no impurities, the full signal could be recovered, although the relaxation behaviour appeared to depend strongly on the preparation method. We observed differences in the spin-lattice relaxation by a factor 20; the longest T1 was observed in a crushed single crystal. This implies that alpha-Al2O3 can only be used as a standard in quantitative analyses if it has been characterized thoroughly. Furthermore, the effective relaxation behaviour for different types of excitation is studied. Finally, a method to measure the spin-lattice relaxation of half-integer quadrupole nuclei is introduced, using a frequency-stepped adiabatic passage (FSAP) to invert the spin system.

Suitability of low-molecular-weight heparin(oid)s and a pentasaccharide for an in vitro human thrombosis model

There is much interest in in vitro thrombosis systems using exclusively human materials for evaluating new drugs. We have previously developed such a model using a perfusion chamber in which whole blood anticoagulated with low-molecular-weight heparin (LMWH) was circulated over the extracellular matrix of endothelial cells that had been stimulated with phorbol myristate acetate to cause tissue factor formation. Here we studied various LMWHs and a pentasaccharide to find out which was most useful in an in vitro thrombosis model. We compared unfractionated heparin, two commercial LMWHs (Fragmin and Fraxiparine), one commercial heparinoid (Orgaran), and a chemically synthesized derivative of the natural pentasaccharide (Org 31550). Blood was anticoagulated with the concentration of each glycosaminoglycan that prevented thrombin formation for at least 3 hours in the test tube (Fragmin, 20 anti-Xa U/mL; Fraxiparine, 40 anti-Xa Institute Choay U/mL; Orgaran, 15 anti-Xa U/mL; Org 31550, 200 anti-Xa U/mL; unfractionated heparin, 5 IU/mL) and recirculated over the matrix of unstimulated cells (no tissue factor in the matrix) and phorbol-stimulated endothelial cells (tissue factor in the matrix). Platelet adhesion, aggregate formation, and fibrin deposition were evaluated. In perfusions over the extracellular matrix of unstimulated cells, the highest platelet adhesion rates were observed with Orgaran. Fibrin deposition was absent with unfractionated heparin in phorbol-stimulated matrix. Increasing amounts of fibrin were observed with Orgaran, Fragmin, and Fraxiparine. Most fibrin was found with the pentasaccharide Org 31550.(ABSTRACT TRUNCATED AT 250 WORDS)

Psychological and speech studies in Rubinstein-Taybi syndrome

Forty individuals with Rubinstein-Taybi syndrome were tested using an extensive test battery to obtain more insight about their intelligence level, social competency, temperament, and behavior as well as articulation and receptive and expressive language level. Examination of individuals in the Netherlands who have this rare syndrome has been extensive, allowing some generalizations to be made. The intelligence level of affected individuals is usually low, although some persons have much higher scores than do others. The tested individuals were remarkably consistent in their social competency, temperament, and behavior. They were able to make good use of their limited verbal abilities. Comparable studies of other groups of persons with a specific syndrome are needed to determine whether the present findings are specific for Rubinstein-Taybi syndrome or may be found among persons with other syndromes.

Possible link between circadian rhythm and heat shock response in Neurospora crassa

3-h pulses of elevated temperatures (30 degrees C, 35 degrees C, 40 degrees C) phase shift the circadian conidiation rhythm of Neurospora crassa. The phase and amplitude of the phase response curves (PRC) were measured in wild type (frq+) and frequency mutants (frq 1, frq 7). The dose dependence of the phase shifts was compared to the dose dependence of total protein synthesis inhibition and heat shock protein induction in the three strains. All processes showed an almost linear dependence on temperature. These experiments and other available data suggest that a temperature increase may act on the circadian rhythm by a process belonging to the heat shock response.

Mesencephalic projections to the facial nucleus in the cat. An autoradiographical tracing study

In 33 cats the projections of different parts of the mesencephalon to the facial nucleus were studied with the aid of the autoradiographical tracing method. The results indicate the existence of many different mesencephalo-facial pathways. The dorsomedial facial subnucleus, containing motoneurons innervating ear muscles, receives afferents from 4 different mesencephalic areas: a, the most rostral mesencephalic reticular formation; b, the nucleus of Darkschewitsch and/or the ventral part of the rostral PAG; c, the interstitial nucleus of Cajal and/or the mesencephalic tegmentum dorsomedial to the red nucleus. These areas project bilaterally by way of an ipsilateral medial tegmental pathway. The medial part of the deep tectum. This area projects bilaterally by way of the tecto-spinal tract. The lateral mesencephalic tegmentum close to the parabigeminal nucleus. This area projects mainly contralaterally by way of a separate contralateral lateral tegmental fiber bundle. The mesencephalic tegmentum just dorsolateral to the red nucleus and perhaps from the dorsolateral red nucleus itself. This area projects contralaterally by way of the rubrospinal tract. The intermediate facial subnucleus containing motoneurons innervating the muscle around the eye, receives afferents from two different mesencephalic areas: The dorsal part of the rostral as well as caudal red nucleus (but not from its caudal pole) and from the dorsally adjoining mesencephalic tegmentum including the area of the nucleus of Darkschewitsch and the interstitial nucleus of Cajal. These areas project contralaterally by way of the contralateral rubrospinal tract. The nucleus of the optic tract and/or the olivary pretectal nucleus. This area projects contralaterally by way of a contralateral medial tegmental pathway. The lateral and ventrolateral facial subnuclei containing motoneurons innervating the muscles around the mouth receive afferents from two different mesencephalic areas: The lateral part of the deep tectal layers. This area projects contralaterally by way of the tecto-spinal tract. The nucleus raphe dorsalis and perhaps the nucleus centralis superior. This area projects by way of the lateral tegmentum of caudal pons and medulla.

A micronucleus method for detection of meiotic micronuclei in male germ cells of mammals

A new rapid micronucleus method is presented for the detection of chromosomal damage induced in spermatocyte stages of mammals. Analysis of micronuclei is done in early spermatids that have been isolated from testis tubules in a special testis isolation medium supplemented with enzymes (collagenase, trypsin and DNAase).

Development of a screening system for detection of somatic mutations. II. The use of peptides and insoluble protein fragments in a non-competitive solid-phase enzyme immunoassay

A system proposed for measurement of mutational risk consists in detection of hemoglobin mutations expressed in erythrocytes. For this detection the production of antibodies specific for Hb variants is essential. Recently we reported a sensitive solid-phase EIA for the production and selection of polyclonal and monoclonal antibodies specific for hemoglobin determinants. An important characteristic of this EIA was the coating of water-insoluble proteins to polystyrene microtiter plates. Here we report that with this system, insoluble protein fragments and small peptides may also be covalently coated to a polystyrene surface. Coating is independent of the length of the peptides. This allows direct, non-competitive titration of the antibody response to small peptides and avoids the drawbacks of competitive assay.

PI (alpha 1-Antitrypsin) subtypes: frequency of PI*M4 in several populations

Sera from different populations (Dutch, Northern and Southern Italians and Spaniards) were screened for PI (alpha 1-antitrypsin) types and subtypes. A polyacrylamide isoelectric focusing method was applied, which consisted of the combined use of an ultra-thin highly cross-linked gel, restricted pH range carrier ampholytes and a separator. This technique enabled easy typing and subtyping of all known PI phenotypes including PI*M subtypes. The frequency of the new PI*M4 allele was lowest of all PI*M alleles (0.0476 in The Netherlands, 0.0371 in Northern Italy, 0.0308 in Southern Italy and 0.0146 in Spain).

Development of a screening system for detection of somatic mutations. I. Enzyme immunoassay for detection of antibodies against specific hemoglobin determinants

A solid-phase enzyme immunoassay for the detection of antibodies, specific for hemoglobin (Hb) is described. The application of glutaraldehyde resulted in a sensitive assay and allowed the use of urea, which is an important advantage if polypeptides not soluble in aqueous buffers are to be used. Mutation-carrying Hb chains can be purified, solubilized in urea and used in the immunoassay to monitor the purification and selection of antibodies specific for these variants. Specific antibodies are the main tools for the development of a hemoglobin-locus mutation system for detection of potentially mutagenic environmental agents. With erythrocytes as target cells, this system permits in vivo monitoring of subjects under exposure. Conventional antibody production, however, frequently turns out to be unsuccessful. The production of monoclonal antibodies has several advantages over conventional antibody production, but a sensitive antibody screening system is essential. Because of the sensitivity and the ease with which a large panel of antibody fractions against a vast panel of Hb antigens can be examined, the described immunoassay has potential value for the screening of hybridoma cultures.