Partial deletion 11q: report of a case with a large terminal deletion 11q21-qter without loss of telomeric sequences, and review of the literature

We describe the cytogenetic findings and the dysmorphic features in a stillborn girl with a large de novo terminal deletion of the long arm of chromosome 11. The karyotype was 46,XX,del(11)(q21qter). By reviewing previous reports of deletion 11q, we found that cleft lip and palate are most frequently seen in proximal 11q deletions involving 11q21. Telomeric staining using the PRINS technique demonstrated normal telomeric sequences in the deleted chromosome 11.

Staining of human telomeres with primed in situ labeling (PRINS)

As described, the PRINS method is a very rapid and reliable way of staining human telomeres. To obtain the maximum frequency of stained telomeres, the primer (CCCTAA)7 should be used, although the average frequency never quite reaches 100%. The frequency is strongly dependent on the age of the individual, being significantly higher in children and newborns than in adults. A difference between the (CCCTAA)7 primer and the complementary primer is demonstrated and a possible explanation is proposed, namely, that gaps in the C-rich strand cause chain elongation termination after the addition of only one dTTP molecule.

Epidemiology of pertussis in Denmark: the impact of herd immunity

BACKGROUND

An evaluation is presented of the Danish pertussis immunization programme, which consists of three injections of plain whole-cell pertussis vaccine given alone at ages 5 weeks, 9 weeks, and 10 months.

DATA

The incidence of pertussis in vaccinated and unvaccinated children since the start of vaccination was obtained from the notification system for infectious diseases. Data for vaccination coverage were obtained from the National Social Security. The data for 1980-1986 were supplemented with data from culture-verified cases and hospitalized cases.

RESULTS

Compared with other countries using four injections, incidence rates in Denmark are high, especially in pre-school years, leaving infants at a relatively high risk for contracting pertussis from siblings. However, compared with the era before general vaccination, the incidence of pertussis has fallen to one-sixteenth of its former levels. Today, only one in 20 vaccinated, and one in six unvaccinated children develop pertussis before the age of 15 years. This considerable fall, which has also occurred among unvaccinated children, is used to elucidate the importance of herd immunity, which, with the relatively high vaccination coverage in Denmark, was found to play a major role.

CONCLUSIONS

The importance of herd immunity is stressed, and it is recommended that a fourth injection of pertussis vaccine is introduced to bring incidence rates down to the very low values found in countries with more intensive vaccination programmes.

[Electromagnetic fields from high-voltage installations and cancer in childhood]

The objective of this population-based case-control study has been to investigate whether residence before and after birth near 50 Hz high voltage installations increases a child's risk of cancer and whether risk correlates with the strength of the magnetic field. One thousand seven hundred and seven children under the age of 15 with either leukaemia, a tumour of the central nervous system, or malignant lymphoma diagnosed in 1968-86 were identified in the Danish Cancer Registry and matched with 4788 population controls. Measures of exposure were proximity before and after birth to existing or former 50-400 kV electrical transmission connections and substations and associated historical electromagnetic fields calculated on the basis of current load on line, phase ordering of line, and distance from the dwelling. A significant association was seen between all major types of childhood cancer combined and exposure to magnetic fields from high voltage installations of > or = 0.4 microT (odds ratio 5.6). At > or = 0.25 microT no significant association was seen (odds ratio 1.5). A possible association was also seen with cases of Hodgkin's disease separately at > or = 0.1 microT. On the basis of these results and additional descriptive data on electricity consumption and incidence of childhood cancer in Denmark since the 1940s it was concluded that the proportion of childhood cancer possibly caused by 50 Hz electromagnetic fields must be small.

[Epidemiology of infectious diseases--analysis of an increase of infectious hepatitis in Hamburg]

In Hamburg, the incidence of reported cases of infectious hepatitis more than doubled from 1990 to 1991. The increase refers to hepatitis A, B and other forms of hepatitis. The seven public health offices and the local ministry for health, works and social affairs in Hamburg have analysed the development in a computer-based retrospective study comparing the 1990 and 1991 data. The predominantly affected age group of hepatitis A shifted from childhood to young adulthood. The importance of travelling to acquire hepatitis A was less than expected. In all forms of hepatitis the large number of IV-drug users and prisoners was striking.

Residence near high voltage facilities and risk of cancer in children

OBJECTIVE

To investigate whether residence before and after birth near 50 Hz high voltage installations increases a child's risk of cancer and whether risk correlates with the strength of the magnetic field.

DESIGN

A population based case-control study.

SETTING

Denmark.

SUBJECTS

1707 children under the age of 15 with leukaemia, tumour of the central nervous system, or malignant lymphoma diagnosed in 1968-86 and 4788 children taken from the central population register.

MAIN OUTCOME MEASURES

Proximity before and after birth to existing or former 50-400 kV electrical transmission connections and substations and associated historical electromagnetic fields calculated on the basis of current load on line, phase ordering of line, and distance from the dwelling.

RESULTS

A significant association was seen between all major types of childhood cancer combined and exposure to magnetic fields from high voltage installations of > or = 0.4 microT (odds ratio 5.6). At > or = 0.25 microT no significant association was seen (odds ratio 1.5). A possible association was also seen with cases of Hodgkin's disease separately at > or = 0.1 microT.

CONCLUSIONS

On the basis these results and additional descriptive data on electricity consumption and incidence of childhood cancer in Denmark since the 1940s it was concluded that the proportion of childhood cancer possibly caused by 50 Hz electromagnetic fields must be small.

First cases of microsporidiosis in Scandinavian patients with AIDS

The first 2 cases of infection with Enterocytozoon bieneusi in Denmark and Scandinavia are reported. Both patients were women and to the best of our knowledge this is the first report of E. bieneusi in female AIDS patients. Both had late stage AIDS, and both had complained of intermittent diarrhoea for more than 1 year. At the time microsporidiosis was diagnosed, no other pathogens causing diarrhoea were found. Immunodeficient patients with chronic unexplained diarrhoea should be investigated for intestinal microsporidiosis, especially as treatment is now available.

A monthly cycle in the plasma concentration of GnRH and the glomerular filtered load of GnRH during second trimester pregnancy

Six healthy women were examined three times a week during the second trimester. The aim of the study was to test the existence of a monthly cycle in plasma GnRH. Because the kidney plays a dominant part in the elimination of small peptides from the circulation by filtration, the filtered load (P-GnRH x GFR) of GnRH was estimated and tested for a cycle. A mathematical model (parabolas overlaid with a cosine curve and containing parameters for cycle length, cycle amplitude and phase) was used in a multivariate analysis of changes in plasma GnRH, creatinine clearance and GnRH filtered load. We found significant monthly cycles in plasma GnRH (p = 0.003) and in GnRH filtered load (p = 0.004), but no significance for a cycle in creatinine clearance. As an intermediate result we demonstrated that the tubular reabsorption of GnRH was unsaturated for all values of plasma GnRH and GnRH filtered load in question. The increased pregnancy level of plasma GnRH originates in part in the placenta, but we assume that the cycle generator is contained in the maternal neuroendocrine system.

Mechanism of killer gene activation. Antisense RNA-dependent RNase III cleavage ensures rapid turn-over of the stable hok, srnB and pndA effector messenger RNAs

The hok/sok, srnB and pnd systems of plasmids R1, F and R438 mediate plasmid maintenance by killing plasmid-free segregants. The systems encode exceptionally stable full-length mRNAs that code for potent cell toxins that kill the cells from within. The systems also produce truncated mRNAs whose appearance is correlated with killing activity. The truncated mRNAs are shortened by 35 to 70 nucleotides in the 3' ends, but have the same 5' ends as the full-length transcripts. Translation of the stable killer mRNAs is regulated by unstable antisense RNAs that are complementary to the leader regions of the full-length and truncated mRNAs. We show here, that both the presence of the antisense RNA and of the host enzyme RNase III is required for rapid cleavage of the truncated mRNAs, and we map the cleavage point in the Hok mRNA in vitro and in vivo to be located between nucleotides +245 and +246. The RNase III cleavage products of the Hok mRNA were found to be very unstable in vivo. Thus, RNase III cleavage seems to be the initial event leading to decay of the killer mRNAs. In an rnc- strain, the truncated mRNA species were found in steady-state cells. This observation indicates that the truncated mRNAs are formed constitutively and independently of the presence of the antisense RNAs. Thus, the antisense RNAs prevent the accumulation of the truncated mRNAs solely by mediating their rapid hydrolysis by RNase III. Furthermore, the generation of the truncated killer mRNAs in the rnc- host indicate that RNase III is dispensable for induction of the killer gene systems. Based on these and on observations obtained previously, we present a molecular model that explains the activation of the killer mRNAs in plasmid-free segregants and after addition of rifampicin.

Permeation resistance of glove materials to agricultural pesticides

The toxicities of many agricultural pesticides require that hand protection be used by persons who mix, load, and apply these products, as specified on the label and material safety data sheet. Selection of gloves for formulations that contain organic solvents is particularly problematic because a solvent that permeates the glove can carry with it the active ingredient of the pesticide formulation. With a test method that measures the simultaneous permeation of the carrier solvent(s) and active ingredient(s), in particular those active ingredients that have low solubility in water and low volatility, over 100 permeation tests (in triplicate) with approximately 20 pesticide formulations were conducted with 13 different glove materials. These results are summarized and generalizations are presented within the perspective of the large base of permeation data for neat chemicals and another large permeation study with pesticides. Key among the findings is that the carrier solvent generally permeates first and at a much higher rate than the active ingredient. Furthermore, the permeation behavior of formulations containing solvents generally mirrored that of neat carrier solvents alone. Thus, insight into the selection of the most appropriate glove material for a given pesticide formulation can be gained from permeation data for neat chemicals. For the types of solvents that may be present in pesticide formulations, preferred materials include nitrile rubber, butyl rubber, and plastic film laminates. Natural rubber and polyvinyl chloride materials generally are not recommended.

A versatile method for integration of genes and gene fusions into the lambda attachment site of Escherichia coli

We have developed a versatile method for integration of modified genes and gene fusions into the bacteriophage lambda attachment site (attB) of the Escherichia coli chromosome. The method relies on two components: (1) a DNA integration cassette, flanked by multiple restriction enzyme sites, which contains the lambda attP site and, as a selectable marker, the Tn5 aphA gene conferring kanamycin resistance (KmR); and (2) a plasmid with the lambda int gene transcribed from the tet promoter. A fragment carrying the gene in question is ligated to the integration cassette, resulting in a circular piece of DNA unable to replicate. The ligation product is then transformed into a strain that contains the int-carrying plasmid. Selection for KmR results in colonies with the cassette integrated into the attB site of the E. coli chromosome. This method was used for integration of several lacZ and phoA promoter fusions. The integration products were analyzed by Southern hybridization. In addition, we found, fortuitously, that the ligated DNA circles could also integrate by homologous recombination, although usually at a much lower frequency than the Int-mediated integration into attB.

Synthesis of a Model Triblock for Novel Thermoplastic Elastomers

Thus far, we have been successful in preparing novel diblock and triblock copolymers comprised of poly(methyl methacrylate) and poly(butyl vinyl ether). Future work will focus on studying the morphology of both the diblock and triblock copolymers. Moreover, we are also interested in synthesizing triblocks with long poly(butyl vinyl ether) segments and short PMMA segments, since these polymers have the potential for exhibiting good elastomeric properties.

A monthly cycle in the adrenocortical function during third trimester pregnancy

Eleven healthy women were examined three times a week during the third trimester. The possibility of monthly cyclical changes in the serum concentrations of cortisol, placental hCG and fetoplacental estradiol was tested because of previous findings of highly significant monthly cycles in aldosterone and progesterone. A semiparametric statistical model was used and a highly significant monthly cycle in serum cortisol was found, whereas the amplitude for a cycle in hCG was barely significant and non-significant for estradiol. The previous findings of monthly cycles in aldosterone and progesterone, using a parametric multivariate model, were retested by the semiparametric method employed for the present publication. The findings of highly significant cycles in aldosterone and progesterone were corroborated. We think that the results indicate the existence of an adrenocortical cycle. We think that the monthly ovarian cycle in the non-pregnant state is paralleled by an adrenocortical cycle, where changes in aldosterone are "linked" with changes in progesterone and changes in cortisol with changes in estrogens. During pregnancy the adrenocortical cycle persists, probably controlled by the maternal hypothalamus. The physiological background for this monthly endocrine cycle during pregnancy is enigmatic.

[Psychological stress before, during and after hospitalization for low back disease. Patients' experience illustrated by qualitative interviews]

Thirteen patients were interviewed 14 days after discharge for low back disease requiring hospitalization with the object of illustrating their experience of the period of waiting for admission, treatment in the primary and secondary health services, their relationships to children living at home during their illness and the effect of the low back disease on sexual life. The patients stated that the period of waiting was the worst, dominated by pain, uncertainty, loss of sleep and lowered self esteem. Treatment in the primary health sector was found to be unsatisfactory as regards relief of pain but satisfactory as regards contact with the general practitioner. In the secondary health sector, relief of pain was found to be satisfactory to varying extents while better contact with the doctor treating the case and the staff as a whole could be desired. Waiting and uncertainty while waiting for a diagnosis and result of treatment, inactivity and the poor contact with the staff were considered by the patients to be contributory causes to the increasing mental vulnerability. The relationship to children living at home was dominated by bad conscience prior to admission and by poor contact during hospitalization. Conditions improved after discharge. Practically no sexual activity occurred during the illness. This was not primarily experienced by the patients as a problem but they feared it might be so in the long run. Patients stated that they required mental support during hospitalization, better information and advice about practical problems after discharge.

[The social and occupational situation of patients 2 1/2 years after hospitalization for low back pain]

Sixty-two of 84 patients hospitalized consecutively for low back pain completed a questionnaire during hospitalization and seven months and 30 months after hospitalization. Out of 43 patients who were occupationally active at the time of admission to hospital, only 23 were still occupied 2 1/2 years after. Fourteen had been granted disability pensions, two were under rehabilitation, two were unemployed and two were on sick leave and had lost their jobs. Patients who were under rehabilitation or on sick leave at the time of admission but had lost their jobs, had now been awarded disability pensions. Seven months after admission, twelve patients had been dismissed from work; of these two were now at work again and seven were disability pensioners. Significant associations were found between rejection from the labour force and the following variables: presence of pain, failure of resumption of work seven months after hospitalization, sick-leave longer than 120 days and dismissal from work after hospitalization. Low educational level and age over 45 years were also associated with rejection, and there was an almost significant trend for patients belonging to social classes 4 and 5. 72% of the patients still had low back pain at least once a week, slightly less than half the patients experienced sexual problems because of the back disease, and more than half had given up at least one leisure activity. 23% used analgesics or non-steroid-anti-inflammatory drugs every day. While 58% considered that the disease was caused by work, only six had applied for and two had been awarded compensation for occupational disease or injury.

[Whooping cough epidemiology in Denmark prior to and after the introduction of whooping cough vaccination. Protective effect of the vaccine and herd immunity]

The epidemiology of whooping cough in Denmark is described on the basis of the notified cases of the disease. The frequency of whooping cough has decreased to approximately one sixteenth of the previous level in children following the introduction of vaccination for whooping cough in 1961. Following change to a programme with only three vaccinations with a weaker, non-aluminium-adsorbed pure whooping cough vaccine in 1970, whooping cough became again slightly more frequent in the nineteen seventies and eighties. No definite reduction in the proportion of cases of whooping cough among infants could be detected although this was what the 1970 programme was particularly aimed at. Isolated deaths from whooping cough still occurred in the eighties, all of these among unvaccinated infants. The risk of whooping cough in an unvaccinated child is approximately one sixth of the risk prior to introduction of vaccination. In a vaccinated child, the risk, as judged from the notified cases, is one twentieth of the risk during the time prior to introduction of vaccination. In all age groups "herd immunity" is considered to have contributed considerably to the reduced incidence. The incidence in Denmark is, however, high compared with the incidence in some other industrialized countries. A vaccination programme with more numerous whooping cough vaccinations and possibly with a more immunogenic vaccine may be recommended on the basis of the strategy aimed at keeping the incidence of whooping cough, and thus the risk of exposure, as low as possible.

A monthly cycle during third trimester pregnancy in the serum concentrations of progesterone and aldosterone and the urinary excretion rate of potassium

Eleven healthy women were examined three times a week during the third trimester. A mathematical model (parabolas overlaid with a cosine curve and containing parameters for cycle length, cycle amplitude and phase) was used in a multivariate analysis of changes in serum progesterone, serum aldosterone, serum osmolality and urinary potassium. A highly significant monthly cycle in progesterone and aldosterone and a significant cycle in the urinary excretion rate of potassium were found. The individual rates of increase in serum progesterone and serum aldosterone were different and uncorrelated, and in the monthly cycle there was a phase difference between them. We think that the changes in serum progesterone and serum aldosterone are controlled by different stimuli and that the control of the cyclical component originates in the maternal neuro-endocrine system.

Isolation, characterization, and nucleotide sequence of appY, a regulatory gene for growth-phase-dependent gene expression in Escherichia coli

A plasmid carrying a regulator gene, designated appY, was found in the screening of an Escherichia coli gene library for clones overproducing AppA, an acid phosphatase which is induced as a culture approaches the stationary phase. In cells containing multicopy plasmids carrying the appY gene, the expression of the chromosomal appY gene was stimulated 10- to 40-fold in the stationary phase and more than 100-fold during exponential growth. The appA plasmid also changed the rate of synthesis of more than 30 other proteins in a growth-phase-dependent way. The appY gene was mapped to 13 min on the E. coli genetic map. The position of the appY gene on the 4.9-kilobase HindIII fragment of the original clone was located by Tn5 mutagenesis and deletion analysis, and the nucleotide sequence of a 1.9-kilobase region containing the gene was determined. The appY gene product was identified as a weakly expressed 243-amino-acid polypeptide which contains a stretch of 20 amino acids showing very good similarity to the conserved DNA-binding domain of repressors and transcriptional activators.