Prediction of lethal pulmonary hypoplasia and chorioamnionitis by assessment of fetal breathing

Twenty-three pregnancies with fetuses at risk for pulmonary hypoplasia were studied weekly until delivery. The amount of time spent in fetal breathing activity was recorded under controlled conditions during 1 h using real-time ultrasound. An amniotic fluid index was determined. The clinicians and the pathologist were unaware of the ultrasound findings. Eight of 23 fetuses did not breathe at the last ultrasound examination. Three babies died of pulmonary hypoplasia and two of these showed fetal breathing before birth. The three deaths were associated with rupture of the membranes at less than or equal to 20 weeks gestation and of greater than or equal to 44 days duration. One infant developed bronchopulmonary dysplasia. The amniotic fluid index in these four pregnancies was low and the newborn infants had limb contractures. Chorioamnionitis/funisitis was noted in 13 placentas. Eight fetuses were assessed for fetal breathing within 2 days of birth. The lack of fetal breathing had sensitivity, specificity, positive and negative predictive values of 0.75 for chorioamnionitis/funisitis. In this pilot study the absence of fetal breathing was of no value in predicting lethal pulmonary hypoplasia, but was related to chorioamnionitis/funisitis. We recommend further studies of fetal breathing in relation to fetal/neonatal infections.

Structural and catalytic properties of a deletion derivative (delta 133-157) of Escherichia coli adenylate kinase

Escherichia coli adenylate kinase (AKe) as well as the enzyme from yeast and mitochondria differs from the muscle cytosolic variant (AK1) by an insertion of 25 amino acid residues that are missing in AK1. The extra sequence, highly homologous in "large" size variants, is situated between residues 133 and 157 in AKe. Removal of 25 codons in the corresponding adk gene resulted in expression of a modified form of adenylate kinase (delta 133-157 AKe) which still conserved 7% of the maximal activity of the wild-type protein. The apparent Km for nucleotide substrates was increased by a factor of 4.6 (ADP), 23 (ATP) or 43 (AMP) in delta 133-157 AKe when compared with the wild-type enzyme. The secondary structure of delta 133-157 AKe, as well as its thermal stability were very similar to the parent protein. However, the deleted protein was much more sensitive than the wild-type enzyme to inactivation by trypsin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of trypsin digested delta 133-157 AKe revealed accumulation of several well defined fragments which were not observed in the case of wild-type enzyme. We conclude that the additional sequence, although necessary for expression of full activity in AKe, is not critical for catalysis. It is perhaps responsible for interaction of enzyme with other cellular components although a different mechanism of water shielding for large and small size variants of AK can be also envisaged.

New possibilities in safety performance and the control of workers' compensation costs

This article describes successful behavioral interventions that improved safety performance and reduced workers' compensation costs in two corporations. The development of a four part program that: (1) shifted the paradigm for positive performance by workers and managers, (2) strengthened the community of work, (3) managed the crises of accidents, and (4) accelerated the return of injured employees to meaningful work is presented. In the two companies, lost time accidents were reduced by 95% and 87%, and accident costs were reduced by 90% and 70%, respectively. The results are discussed in terms of the critical roles played and choices made by managers in establishing a meaningful work culture, and the ethics which guide workers' and managers' behavior in decisions related to the use and abuse of the workers' compensation system.

Structural and ligand-binding properties of a truncated form of Bacillus anthracis adenylate cyclase and of a catalytically inactive variant in which glutamine substitutes for lysine-346

A truncated, 541-residue-long, Bacillus anthracis adenylate cyclase was expressed in Escherichia coli. The purified protein (CYA 62) exhibited catalytic and CaM-binding properties identical with those of the wild-type enzyme secreted by B. anthracis. The analysis of the secondary structure of the CYA 62 protein by Fourier transform infrared spectroscopy and circular dichroism revealed the dominance of beta-type structure. The protein shows a relatively low thermal stability with the midpoint denaturation temperature at 45 degrees C. A catalytically inactive variant of CYA 62 in which Gln substituted for Lys-346 (CYA 62 K346Q) was comparatively analyzed for its secondary structure and thermal stability, as well as ligand-binding properties with fluorescent derivatives of ATP and calmodulin. The K346Q variant of CYA 62 has a similar secondary structure and comparable calmodulin binding properties to those of the parent protein and exhibits only slightly reduced thermal stability (the apparent midpoint denaturation temperature is at 43 degrees C). Despite these similarities, the binding of 3'-anthraniloyl-2'-deoxy-ATP (a fluorescent ATP analogue) to the modified protein is severely impaired, from which we conclude that the prime function of Lys-346 in the wild-type enzyme from B. anthracis is to ensure tight binding of the nucleotide substrate to the active site.

Intrinsic fluorescence of a truncated Bordetella pertussis adenylate cyclase expressed in Escherichia coli

A truncated, 432 residue long, Bordetella pertussis adenylate cyclase expressed in Escherichia coli was analyzed for intrinsic fluorescence properties. The two tryptophans (Trp69 and Trp242) of adenylate cyclase, each situated in close proximity to residues important for catalysis or binding of calmodulin (CaM), produced overlapping fluorescence emission bands upon excitation at 295 nm. CaM, alone or in association with low concentrations of urea, induced important modifications in the spectra of adenylate cyclase such as shifts of the maxima and change in the shape of the bands. From these changes and from the fluorescence spectrum of a modified form of adenylate cyclase, in which a valine residue was substituted for Trp242, it was deduced that, upon binding of CaM to the wild-type adenylate cyclase, only the environment of Trp242 was affected. The fluorescence maximum of this residue, which is more exposed to the solvent than Trp69 in the absence of CaM, is shifted by 13 nm to shorter wavelength upon interaction of protein with its activator. Trypsin cleaved adenylate cyclase into two fragments, one carrying the catalytic domain, and the second carrying the CaM-binding domain (Ladant et al., 1989). The isolated peptides conserved most of the environment around their single tryptophan residues, as in the intact adenylate cyclase, which suggests that the two domains of truncated B. pertussis adenylate cyclase also conserved most of their three-dimensional structure in the isolated forms.

Structural and catalytic role of arginine 88 in Escherichia coli adenylate kinase as evidenced by chemical modification and site-directed mutagenesis

Phenylglyoxal inactivates Escherichia coli adenylate kinase by modifying a single arginine residue (Arg-88). ATP, ADP, P1,P5-di(adenosine 5')-pentaphosphate, and to a lesser extent AMP protect the enzyme against inactivation by phenylglyoxal. Site-directed mutagenesis of Arg-88 to glycine yields a modified form of adenylate kinase (RG88 mutant) closely related structurally to the wild-type protein as indicated by Fourier transform infrared spectroscopy, differential scanning calorimetry, and limited proteolysis. However, this modified protein has only 1% of the maximum catalytic activity of the wild-type enzyme and 5- and 85-fold higher apparent Km values for ATP and AMP, respectively, than the parent adenylate kinase. Arg-88, which is a highly conserved residue in all known molecular forms of adenylate kinases (corresponding to Arg-97 in muscle cytosolic enzyme), should be located inside a big cleft of the molecule, close to the phosphate-binding loop. It possibly stabilizes the transferable gamma-phosphate group from ATP to AMP in the transition state.

[The left ventricular functional parameter in M-mode echocardiography in various administration rates of a loading dose of theophylline in premature infants]

The aim of study was to show a positive effect of theophylline on the cardiac pump function immediately after i.v. bolus injection of the loading dose. Therefore we recorded m-mode echocardiograms before and immediately after bolus injection (over 2-3 min) of 6 mg/kg theophylline. On studying 12 preterm infants we observed a reduction of the left ventricular shortening fraction and circumferential shortening velocity. In the second part of the study we administered the same dose of theophylline over a period of 20 min. No significant differences in m-mode echocardiographic parameters before and after infusion were seen. We attribute these results to incalculable effects of theophylline preload, wall distension, and afterload. Nonetheless slow application of theophylline loading dose is recommended in preterm infants.

Conservative replacement of methionine by norleucine in Escherichia coli adenylate kinase

Escherichia coli grown in limited methionine and excess norleucine media accumulate cyanogen bromide-resistant species of proteins after the methionine supply is exhausted. Bacteria, transformed by recombinant plasmid pIPD37 carrying the adk gene and grown under limiting methionine and excess norleucine, synthesize 16-20% of adenylate kinase molecules having all 6 methionine residues replaced by norleucine. Species showing only partial replacement of methionine residues by norleucine are identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after cyanogen bromide treatment of pure enzyme. Norleucine-substituted adenylate kinase shows structural and catalytic properties similar to the wild-type protein as indicated by circular dichroism spectroscopy and kinetic experiments but exhibits a much higher resistance to hydrogen peroxide inactivation under denaturing conditions.

[Transitory prolongation of QT time in severely ill premature and newborn infants]

Over 24 months in a Neonatal Intensive Care Unit 118 electrocardiograms were recorded in the first three days of life. 12 preterm and term newborns had a corrected QT-time-prolongation over 0.44 s. Measurement of the ionized calcium level in these children revealed hypocalcemia in only four as a reason for QT-time-prolongation. One child had hypokalemia, one child suffered from accidental Bupivacain injection. In the other six children no known reasons for QT-time-prolongation could be found. The QT-time-prolongation persisted for a maximum of three months, no inherited QT-syndrome existed. We discuss a correlation of these transitory QT-time-prolongation with asphyxia which preexisted in all six children. Influences on catecholamine receptors of myocardium or changes in central sympathicotonus may be assumed.

Some Theory and Applications of Confirmatory Second-Order Factor Analysis

This paper shows how confirmatory factor analysis can be used to test second- (and higher-) order factor models in the areas of the structure of abilities, allometry, and the separation of specific and error variance estimates. In the latter area, an idea of Joreskog's is extended to include a new conceptualization of the estimation of validity. Second-order models are placed in a hierarchy of factor analysis models, which shows how the fit of various models can be compared. The concept of discriminability is introduced to describe a situation in which two models may both be identified, and yet the goodness-of-fit for both will be the same. This problem can usually be avoided by careful design of a study. Several examples are discussed.

[Neonatal emergency: bupivacaine poisoning following maternal caudal anesthesia]

After maternal caudal anesthesia with bupivacaine life-threatening symptoms of bupivacaine intoxication occurred in the newborn. The local anesthetic had been injected directly into the fetal scalp. Cardiac shock caused by sinus bradycardia and impaired intracardial conduction (wide QRS-complex) was treated successfully. Seizures were absent. The bupivacain plasma level 90 min post partum was 3.6 mg/l, the elimination half-life 14 h. The symptoms presented in the newborn--especially the cardiovascular changes--coincide well with the results of animal experiments reported in the literature.

Occurrence of carotenoids and sporopollenin in Nanochlorum eucaryotum, a novel marine alga with unusual characteristics

Pigment analysis of Nanochlorum eucaryotum on two strains grown under different gaseous conditions was performed. Air-gassed control cultures did not differ qualitatively with respect to the content of chlorophylls a and b, carotenes alpha and beta, lutein, violaxanthin, neoxanthin and cryptoxanthin in comparison with cultures grown under natural gas. The absolute pigment content per cell increased in cultures grown with natural gas. Growth of N. eucaryotum depends on CO2 which is present in concentrations up to 2.0 vol% in natural gas. N. eucaryotum cannot utilize methane and is therefore not methylotrophic. In cultures of N. eucaryotum grown with natural gas and in air-gassed cultures under nitrogen deficient conditions the secondary carotenoids canthaxanthin and astaxanthin could be detected. In air-gassed cultures of strain N. eucaryotum Colona the same secondary carotenoids have been found, while secondary carotenoids were never found in strain N. eucaryotum Mainz. Cell walls of N. eucaryotum always contain sporopollenin as confirmed by isolation, elemental analysis, infrared absorption spectrophotometry, acetolysis-resistance and electron microscopy.

The effects of a personal phone call prompt on blood donor commitment

There is a need to investigate procedures that can motivate individuals to attend blood drives. Low rates of attendance are partly due to the failure of many to fulfill their pledges to donate blood. This study examined the use of personal phone calls to prompt college-age blood donors to fulfill their commitments. The results indicated that a remainder call was effective in prompting pledged donors to attend a college drive. The phone call prompt might have been effective because of the social pressure which the recruiter exerted on the donors. Implications of these findings for blood donor recruitment efforts as well as the field of community psychology are discussed.

Familial occurrence of dermatomyositis and progressive scleroderma after injection of a local anaesthetic for dental treatment

In an 11-year-old boy severe dermatomyositis occurred a few days after injection in the jaw of a local anaesthetic of the amide type for tooth extraction. The patient's grandmother was affected by progressive scleroderma at the age of 34 years, also after injection of a local anaesthetic for dental treatment. Both cases are discussed with special reference to the immuno-genetic aspects of the origin of dermatomyositis.