Reducing drug prescription errors and adverse drug events by application of a probabilistic, machine-learning based clinical decision support system in an inpatient setting

BACKGROUND

Drug prescription errors are made, worldwide, on a daily basis, resulting in a high burden of morbidity and mortality. Existing rule-based systems for prevention of such errors are unsuccessful and associated with substantial burden of false alerts.

OBJECTIVE

In this prospective study, we evaluated the accuracy, validity, and clinical usefulness of medication error alerts generated by a novel system using outlier detection screening algorithms, used on top of a legacy standard system, in a real-life inpatient setting.

MATERIALS AND METHODS

We integrated a novel outlier system into an existing electronic medical record system, in a single medical ward in a tertiary medical center. The system monitored all drug prescriptions written during 16 months. The department's staff assessed all alerts for accuracy, clinical validity, and usefulness. We recorded all physician's real-time responses to alerts generated.

RESULTS

The alert burden generated by the system was low, with alerts generated for 0.4% of all medication orders. Sixty percent of the alerts were flagged after the medication was already dispensed following changes in patients' status which necessitated medication changes (eg, changes in vital signs). Eighty-five percent of the alerts were confirmed clinically valid, and 80% were considered clinically useful. Forty-three percent of the alerts caused changes in subsequent medical orders.

CONCLUSION

A clinical decision support system that used a probabilistic, machine-learning approach based on statistically derived outliers to detect medication errors generated clinically useful alerts. The system had high accuracy, low alert burden and low false-positive rate, and led to changes in subsequent orders.

Baseline low ALT activity is associated with increased long-term mortality after COPD exacerbations

BACKGROUND

COPD exacerbations have negative impact on patients' survival. Several risk factors for grave outcomes of such exacerbations have been descried. Muscle dysfunction and mass loss were shown to impact negatively on prognosis and survival. Low activity of the enzyme ALT (Alanine amino-transferase) in the blood is a known indicator for sarcopenia and frailty, however, no previous studies addressed the association of low ALT amongst patients hospitalized due to COPD exacerbation and long-term survival.

METHODS

This is a historic prospective cohort study of patients hospitalized due to acute COPD exacerbation.

RESULTS

Included were 232 consecutive COPD exacerbation patients. The median time of follow-up was 34.9 months (IQR 23.13-41.73 months). During this period 104 (44.8%) patients died. All patients were grouped to quartiles according to blood ALT levels (after exclusion of cases considered to have hepatic tissue damage (ALT > 40 IU)). The risk of long-term mortality increased, in a statistically significant manner, amongst patients with low ALT values: the median survival of patients with ALT < 11 IU was 18.5 months only while the median survival for the rest of the study group was not reached. For ALT < 11 IU; 12-16 IU; 17-20 IU and > 21 IU the mortality rates were 69%; 40.9%; 36.3 and 25% respectively (p <  0.001 for comparison of lower quartile with upper three quartiles). The crude hazard ratio for mortality amongst patients with ALT levels lower than 11 IU was 2.37 (95% CI; 1.6-3.5). This increased risk of mortality remained significant after adjustment for age, weight, creatinine, albumin concentration and cardiovascular diseases (HR = 1.83; 95% CI 1.08-3.1, p <  0.05).

CONCLUSIONS

Low ALT values, a biomarker of sarcopenia and frailty, are associated with poor long-term survival amongst patients hospitalized due to COPD exacerbation.

Atomic Oxygen Durability of Uncoated and Coated High-Frequency Circuit Materials

Different materials were considered for high-frequency circuit applications requiring exposure to low Earth orbit (LEO) space environment. The potential candidates were TMM3 which is a ceramic thermoset polymer composite, and RO4003 which is a glass reinforced hydrocarbon/ceramic laminate, both manufactured by Rogers Corporation (USA). Various constituents of the space environment can affect these materials’ properties. Atomic oxygen is considered the most hazardous component since it may cause degradation of these materials by etching and/or changing the chemical composition. The candidate materials were tested by exposure to different equivalent atomic oxygen (ATOX) fluences of up to 1.9 × 1021 atoms cm−2. The effects of the atomic oxygen exposures were studied by means of scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), atomic force microscopy (AFM) and mass loss measurements. Both materials were degraded under ATOX exposure, resulting in intensive mass loss as well as changes in surface morphology and chemistry. In order to protect these materials in the LEO environment several protective coatings were evaluated for TMM3. The protective coatings tested were SiO2, CV1144-0 (a clear silicone coating) and SG120FD (a white silicone paint). SG120FD was found to provide the best protection against ATOX irradiation attack, while CV1144-0 provided a sufficient, though somewhat inferior protection.

A critical study of the generality of the two step two electron pathway for water splitting by application of a C3N4/MnO2 photocatalyst

A novel C3N4-CDot composite photocatalyst was very recently shown to be highly efficient and very stable in water splitting by solar radiation without using any sacrificial reagent (J. Liu, et al., Science, 2015, 347(6225), 970). This photocatalyst utilizes a two-electron/two-step process in which the production of H2O2 and H2 is photocatalyzed by using C3N4 in the first step and H2O2 is decomposed by using CDots in the second step. The present work is a study on the generality of this approach by application of a C3N4/MnO2 catalyst. This new catalyst indeed splits water by a two step process in a stable way, without any sacrificial agent. It was however found that though the absorbance of the new catalyst in the visible range of 500-600 nm is much larger than that of the C3N4-CDot catalyst, its water splitting efficiency is much lower. These findings add insight into and assist in the further optimization of this new class of photocatalysts to meet the requirements of commercial water splitting systems.

Sub-chronic (13-week) oral toxicity study, preceded by an in utero exposure phase and genotoxicity studies with fish source phosphatidylserine in rats

The safety of fish phosphatidylserine (PS) conjugated to DHA (InCog™) was examined in a series of toxicology studies as first step to support future use in infants and general population using in vitro genotoxicity tests and in a sub-chronic toxicity study with an in-utero exposure phase. PS is a major lipid in the cell membrane, active in various membrane-mediated processes. PS-DHA, present in human milk, has been suggested to be important for early brain development. Rats were exposed to diets containing 1.5%, 3% or 4.5% InCog or two control diets. Parental (F0) animals were fed throughout mating, gestation and lactation. Subsequently, a subchronic, 13-week study was conducted on the F1 animals followed by 4 weeks of recovery. The genotoxicity tests showed no mutagenicity potential. No significant toxicological findings were found in the F0 rats or the F1 pups. In the 13-weeks study, an increase in the presence of renal minimal-mild multifocal corticomedullary mineralization was noted in nine females of the high-dose group. This change was not associated with any inflammatory or degenerative changes in the kidneys. The no-observed-adverse-effect level (NOAEL) in the present study was placed at 3% in the diet (mid-dose group), equivalent to an overall intake of at least 2.1 g InCog/kg bw/day in the F1 generation.

Oriented Graphitic Carbon Film Grown by Mass-Selected Ion Beam Deposition at Elevated Temperatures

Mass-selected ion-beam deposition using 120 eV C+ ions has been used to grow a carbon film on a Si substrate held at 200° C. The structure of the film has been characterized by transmission electron microscopy and electron energy loss spectroscopy. The film is graphitic and highly oriented with the c-axis lying parallel to the substrate. Moreover, the film is under significant biaxial stress such that the graphitic layer spacing is reduced by 4% from that of ambient pressure graphite. This oriented structure evolves due to the mobility of the carbon atoms at 200 °C. The material is sufficiently crystalline on the nanometer scale so as to produce Bragg diffraction discs in a convergent beam electron diffraction pattern using a 2.5 nm probe.

Structures and energetics of hydrogen-terminated silicon nanowire surfaces

The analysis and density-functional tight-binding simulations of possible configurations of silicon nanowires (SiNWs) enclosed by low-index surfaces reveal a number of remarkable features. For wires along <100>, <110>, and <111> directions, many low-index facet configurations and cross sections are possible, making their controlled growth difficult. The 112 wires are the most attractive for research and applications because they have only one configuration of enclosing low-index facets with a rectangular cross section, enclosed with the most stable (111) facet and the (110) facet next to it. In general, the stability of the SiNWs is determined by a balance between (1) minimization of the surface energy gamma(111)<gamma(110)<gamma(001), and (2) minimization of the surface-to-volume ratio [svr; svr(hexagonal)>svr(rectangular)>svr(triangular)]. The energy band gaps follow the order of <100>wires > <112>wires > <111>wires > <110>wires. The results are compared with our recent scanning tunneling microscopy and transmission electron microscopy data.

Visualization of diamond nucleation and growth from energetic species

The mystery of diamond nucleation by energetic species is resolved via a special deposition scheme. The evolution of the precursor material for diamond nucleation and the development of the nanodiamond crystallites are visualized by high resolution electron microscopy and other spectroscopies. The diamond precipitation and growth are explained in terms of our recently proposed mechanism [Science 297, 1531 (2002)]]: (i) precipitation of sp(3) clusters a small fraction of which are perfect diamond; (ii) growth of diamond crystallites by preferential displacement of amorphous carbon atoms leaving diamond atoms intact. This general scheme is applicable to other materials such as cubic boron nitride.

The mechanism of diamond nucleation from energetic species

A model for diamond nucleation by energetic species (for example, bias-enhanced nucleation) is proposed. It involves spontaneous bulk nucleation of a diamond embryo cluster in a dense, amorphous carbon hydrogenated matrix; stabilization of the cluster by favorable boundary conditions of nucleation sites and hydrogen termination; and ion bombardment-induced growth through a preferential displacement mechanism. The model is substantiated by density functional tight-binding molecular dynamics simulations and an experimental study of the structure of bias-enhanced and ion beam-nucleated films. The model is also applicable to the nucleation of other materials by energetic species, such as cubic boron nitride.

Nanostructure. Epitaxial diamond polytypes on silicon

Carbon is unique in the variety of configurations it can adopt with itself and other elements. Here we show how ion beams can be used to nanostructure various diamond polytypes, epitaxially aligning them to a silicon substrate. The ready controllability of ion beams, which are already used to manufacture submicrometre-scale devices, means that our findings should enable new carbon and non-carbon materials to be nanostructured for a host of applications.

Role of metal ions in coupling between chemical catalysis and conformational changes in ATP synthase

Isolated chloroplast ATP synthase (CF0F1) was used for determination of the structure-function relation by measuring the effect of divalent metal ions on the properties of ATPase. Mg2+ ions were more efficient catalysts than Ca2+ ions as indicated by Kcat/Km of 55.2 and 5.4, respectively. Other activity parameters related to binding, such as the Km of MATP and Ki of MADP, indicated a stronger binding in the presence of Mg2+ as seen from a Mg2+/Ca2+ ratio of 2.8 and 3.8, respectively. Strong binding of Ca2+ ions with a Kd of 0.03 +/- 00.6 microM-1 was detected only in the presence of ADP probably because of the positive interactive effect of CaADP as indicated in the inhibition properties. Mg2+ ions were more efficient catalysts also in other forms of the enzyme such as in the thylakoid membrane, in isolated CF0F1 and in CF1. The Mg2+/Ca2+ ratio of Kcat/Km was 5.3, 10.2 and 1.5 for the thylakoid membrane enzyme, the isolated CF0F1 and the soluble CF1 respectively. This indicated that Ca2+ ions became less efficient catalysts in the more intact and integrated enzyme while Mg2+ ions were as efficient in all forms of the enzyme. Unlike Mg2+, Ca2+ ions also did not support proton-coupled ATP synthesis and ATP driven proton pumping. It is suggested that the differences in the ligand structure of these two ions might be the reason for the differential function. An average 0.3 A shorter bond length of octahedral first coordination in Ca2+ ions caused a weaker binding of CaATP than that of MgATP. The effect of differential binding is discussed in relation to the binding of the transition state intermediate and to the rate of product release.

Higher than expected carrier rates for familial Mediterranean fever in various Jewish ethnic groups

Familial Mediterranean fever (FMF) is an autosomal recessive disease characterised by recurrent attacks of inflammation of serosal membranes. Amyloidosis leading to renal failure is the most severe complication in untreated patients. In Israel FMF is most frequent among Jews of North African origin. Recently the causative gene (MEFV) has been found and the common mutations characterised. The aim of this study was to investigate the carrier rates of the common MEFV mutations among 400 healthy members of four different ethnic groups (100 in each group) in Israel, and to compare the distribution of the different mutations between FMF carriers and patients. We found a high frequency of carriers among Jews from the various ethnic groups. In North African Jews it was 22%, in Iraqi Jews 39%, in Ashkenazi Jews 21%, and in Iranian Jews 6%. The distribution of the four most common MEFV mutations among healthy individuals (M694V 29%, V726A 16%, M6801 2% and E148Q 53%) was significantly different (P < 0.003) from that found in patients (M694V 84.4%, V726A 9.0%, M6801 0% and E148Q 6.6%). Six healthy asymptomatic individuals were found to carry mutations in both alleles: two homozygotes for E148Q and four compound heterozygotes E148Q/other. These results demonstrate a very high carrier rate among all Jewish ethnic groups. They confirm that mutation E148Q is associated with a milder phenotype, which explains the lower prevalence of FMF among the Ashkenazi and Iraqi Jews. This study raises the question of the need for molecular screening for M694V homozygotes in the Israeli North African Jewish community.

A nucleation site and mechanism leading to epitaxial growth of diamond films

A diamond nucleation site responsible for epitaxial growth of diamond on silicon by chemical vapor deposition (CVD) is identified in high-resolution transmission electron microscopic images. Other sites in the same sample leading to polycrystalline growth, but deleterious to epitaxial CVD growth, are also described. A mechanism for the heteroepitaxial growth of diamond is suggested, in which etching of the nondiamond carbon binder exposes and removes nonadherent nanodiamond nuclei, leaving intact only those directly nucleated on the silicon substrate. This work enhances our understanding of diamond nucleation and heteroepitaxial growth and its potential applications.

The effect of typing frequency and speed on the incidence of upper extremity cumulative trauma disorder

Typing in the work setting, with its emphasis on speed, force and repetitive movements and its tendency to be performed under less than optimum conditions has been one of the major causes of upper extremity cumulative trauma disorder (CTD). This disorder, also known as overuse syndrome, is a chronic condition believed to result from habitual overuse of the digits, hands or arms. The objective of this study was to examine the relationship between typing habits, specifically the influence of typing frequency, speed and style, on the incidence of injury. One hundred Israeli female typists aged between 20 and 60 years with no prior history of orthopedic or neurological disease participated in the study. Data collection took place at the work setting and consisted of a clinical evaluation of the upper extremities and trunk, a typing test, and a questionnaire which included questions concerning demographic information, occupational history, and upper extremity usage in the home and at work. Subjects were asked whether they had suffered from pain or other symptoms in the upper extremity (shoulder, arm, forearm, elbow or hand) on more than three occasions in the last year or on one occasion lasting more than a week. Subjects who answered no to this question were designated as 'non-sufferers'. Those who answered yes to the question were designated 'sufferers'. The 100 women who participated in the study represented a wide range of ages and educational levels. The variables describing on-the-job performance showed a wide range of values. Similar variability was found in the anthropometric variables. On the basis of the subjective criterion, 40 of the women belonged to the group labeled 'sufferers'. The remaining 60 subjects belonged to the group of 'non-sufferers'. The Odd's ratio test (OR), a common statistical procedure for risk factor estimation, was used to determine threshold levels associated with the development of CTD. Age, hours worked per week, typing speed, and years worked as a typist were variables in which at least one cut-off value generated a significant OR. The delineation of factors associated with typists who are classified as 'sufferers' establishes a portrait of the typical worker at risk for the development of CTD and provides insight into ways in which employers, clinicians and workers themselves could reduce the risk of CTD.

Inhibition of chloroplast CF1-ATPase by vanadate

Inhibition of ATPase activity by vanadate, having K1/2 of 0.5 mM, was demonstrated in the CF1-ATPase. The Ca(2+)-dependent ATPase activity of the isolated enzyme was inhibited in an allosteric manner by vanadate with a Hill coefficient of 3.19 +/- 0.6. Vanadate also inhibited ATPase and Pi-ATP exchange activities of the chloroplast membrane-bound enzyme. Using 51V NMR it was demonstrated that ATP caused partial release of about 1.87 equivalents while ADP caused additional binding of approximately 1.46 equivalents of vanadate, when added to a solution containing CF1 equilibrated with vanadate. The relevance of these results to a possible involvement of a pentacovalent phosphate as transition state intermediate in the hydrolysis of ATP by CF1-ATPase is discussed.

[Prostatic specific antigen for detection and monitoring of prostatic cancer]

Prostatic specific antigen (PSA) can be detected in normal and benign hypertrophic prostates, as well as in prostatic cancer and its metastases. Since it appears in the serum, this glycoprotein has become an established marker for the detection and monitoring of prostate cancer. Using a radioimmunoassay (CIS--Biointernational, France), we found serum PSA levels higher than 4 ng/ml in 55 of 58 patients with prostatic cancer. The concentrations were proportional to tumor stage: significantly higher in stages C and D than in stages A and B (p less than 0.002). In all 6 cases with occult prostatic carcinoma (stage A), levels were higher than 15 ng/ml. PSA was found to be a good indicator of response to therapy, as well as a marker of tumor progression during follow-up. After radical prostatectomy serum PSA levels decreased to below 1 ng/ml. Following radiotherapy levels returned to normal within 1-6 months in 8 of 11 patients. In 21 of 23 with metastases serum PSA decreased during hormonal treatment. In 3 who responded initially to hormonal therapy, levels increased before clinical manifestation of tumor progression. We conclude that PSA is a sensitive serum marker for the diagnosis of prostatic cancer in cases of metastatic disease of unknown origin, as well as for monitoring the response to treatment of prostatic carcinoma. The use of PSA serum levels for screening for prostatic cancer is still controversial.

Spheroplast-derived membrane vesicles from Rhodobacter capsulatus cells catalyzing nucleotide transport

Rodobacter capsulatus cells, which were cultured anaerobically in high light intensity, had fewer foldings in the cytoplasmic membrane than those which were grown in lower light intensities. Spheroplast-derived membrane fractions obtained from cells cultured under high light intensity contained a high yield of large right-side-out membrane vesicles. The right-side-out vesicles catalyzed reversible light-induced proton efflux as did intact cells. Nucleotide transport activity was also catalyzed by these membrane vesicles. This activity was indirectly monitored by measurement of photophosphorylation or hydrolysis of externally added diphospho- and triphosphonucleosides. These enzymatic activities occur inside the cytoplasmic membrane of spheroplasts and membrane vesicles and therefore require the transport of the externally added reagents. The indirect measurements of transport were complemented by the demonstration of direct uptake of radiolabeled nucleotides into the membrane vesicles. These data support the suggestion that a nucleotide transporter located in the cytoplasmic membrane of R. capsulatus bacteria mediates these activities.

Nucleotide transport in Rhodobacter capsulatus

Cytoplasmic membrane vesicles isolated from the gram-negative photosynthetic bacterium Rhodobacter capsulatus catalyzed the transport of nucleotides. No transport occurred in the intact bacteria unless they were pretreated with EDTA. The transport rate was measured by incorporation of radioactive phosphate into externally added ADP or by incorporation of nonradioactive phosphate into added labeled ADP. The catalytic activities which utilized the added ADP were photosynthetic ATP synthesis, Pi-ADP exchange, and adenylate kinase. These activities were shown to occur on the cytoplasmic side of the internal membrane. The products were found in the outer medium. The rate of nucleotide transport across the membranes was comparable to the rate of photophosphorylation. These results indicated that nucleotides can be transported across the cytoplasmic membrane but not across the outer membrane of the native R. capsulatus cell. Therefore, by analogy to the mitochondrial ATP-ADP translocator, the exchange might function as an energy transfer system to the periplasm of these bacteria.

Epitaxial Growth of Diamond Films on Si(111) at Room Temperature by Mass-Selected Low-Energy C + Beams

Diamond films ( approximately 0.7 micrometer thick) have been epitaxially grown on Si(111) substrates at room temperature with mass-selected 120-electronvolt C(+) ions. The diamond reflections observed in x-ray diffraction are well localized at their predicted positions, indicating that (i) the diamond(111) and (220) planes are parallel to the Si(111) and (220), respectively; (ii) the diamond rotational spread around its (111) normal is approximately 1.7 degrees ; and (iii) the mosaic block size is approximately 150 A. The film growth is discussed in terms of subplantation-a shallow subsurface implantation model. This discovery is an important step toward diamond semiconductor devices.

Fertility following conservative surgery for tubal pregnancy

Eighty seven conservative surgical interventions for unruptured tubal pregnancy were performed on 83 patients. Salpingotomy was performed in 66 cases and expression of tubal pregnancy in 21 cases. In this patient group, 76.7% (56 out of 73) experienced intra-uterine pregnancy following surgery and 71.2% (52 out of 73) had a live birth. The recurrence rate of tubal pregnancy was 12.3%. Of the 42 patients with a normal contralateral tube, 36 (85.7%) had an intra-uterine pregnancy, 80.9% had a live birth and 7.1% had a recurrent tubal pregnancy. Sixty percent of the patients who underwent operation on their single tube, had a live birth and 66.6% had an intra-uterine pregnancy; the recurrence of tubal pregnancy in this group was 26.6%. No recurrence of tubal pregnancy was found in the group of patients who underwent expression of tubal gestation. It is suggested that the expression of tubal gestation (milking) is a safe procedure for conserving future fertility, and that the indications for conservative surgical management in patients with unruptured tubal gestation should be broadened to include all patients interested in future pregnancies, regardless of the current state of the contralateral tube.

Structure-activity relationships in the mutagenicity of N-substituted derivatives of phenanthrene-9,10-imine

A series of K-region, N-substituted phenanthrene imines were tested for mutagenicity in Salmonella typhimurium TA100. All chemicals were mutagenic in the absence of an exogenous metabolic activation system. The apparent decay times of the mutagenic species in diffusion plates and their alkylating activities were also measured. The unsubstituted phenanthrene-9,10-imine was approximately 70-fold more mutagenic than the corresponding phenanthrene-9,10-oxide. N-substitution with electron-releasing groups resulted in chemicals that were more mutagenic than those substituted with electron-withdrawing groups. The mutagenic activity of the latter group of chemicals was comparable with that of phenanthrene-9,10-oxide. Except for N-chlorophenanthrene imine, both alkylation of p-nitrothiophenol and apparent decay times in diffusion plates were inversely correlated with mutagenicity. It is hypothesized that reactivity towards p-nitrothiophenol (alkylating activity) and mutagenicity reflect different reactions, in contrast to other chemical mutagens. The results suggest that the high potency of phenanthrene imines as mutagens is possibly due to DNA binding via an aziridinium ion rather than a carbonium ion.

Modulation by divalent metal ions of the autocatalytic reactivity of adenosinetriphosphatase from chloroplasts

A nonlinear, pre-steady-state initial rate of ATP hydrolysis is obtained on the addition of a divalent metal ion--ATP complex to a heat-activated coupling factor 1 isolated from chloroplasts. The acceleration of the initial rate follows first-order kinetics. The observed first-order kinetic constant (kobsd) changes with the concentration of the substrate, reaching half-maximal value at the Km for ATP hydrolysis. Preincubation of the enzyme with divalent metal ions decreases the kobsd from 1 to 0.04 s-1. Saturation of the divalent metal ion effect was obtained at the micromolar range. It is suggested that the autocatalysis is a result of early stages in ATP hydrolysis which induce conformational changes in the enzyme. Binding of divalent metal ions in the absence of ATP slows down this change.

Dexamethasone for prevention of respiratory distress syndrome: multiple perinatal factors

Antepartum dexamethasone administration was associated with a significant lowering of the incidence of respiratory distress syndrome (RDS) and with marked reduction of early neonatal mortality in premature infants. Dexamethasone had its greatest effect in infants delivered between 28 and 32 weeks' gestation (P < .001), and the difference was still significant up to 34 weeks' gestation (P < .05). Although the effect of dexamethasone was more marked in patients with intact membranes, it was also effective in those with prolonged rupture of the membranes. Membrane condition before delivery was unrelated to the incidence of RDS. The effectiveness of dexamethasone was analyzed with respect to the condition of the infant at delivery, the mode of delivery, and multiple births. As compared to the controls, dexamethasone was most effective in singletons, infants delivered vaginally, and those with high Apgar scores. The effect of dexamethasone was not significant in twins, breech deliveries, cesarean section deliveries, or infants with low Apgar scores. The effects of dexamethasone appear to be modified by intrauterine asphyxia. Dexamethasone therapy cannot be substituted for optimal delivery conditions of the premature.

Umbilical mass as a presenting symptom of endometrial adenocarcinoma

A case of an umbilical mass as a primary presenting symptom of otherwise asymptomatic endometrial adenocarcinoma is reported. The pertinent literature is reviewed with regard to the relation of the umbilical mass to metastatic carcinoma.

Delivery at 40 years of age and over

This is a retrospective review of 494 deliveries during a 10-year period in women aged 40 or more years. A decline in the incidence of deliveries in this age group was noted, from 2.1% in 1965 to 1.2% in 1974. An increased frequency of complications during pregnancy and delivery, a high rate of cesarean sections, and increased perinatal mortality rate, and more congenital malformations were recorded as compared with both a control group of randomly selected grand multiparas and a general obstetric population group of patients under the age of 40 years. The fetal outcome improved during the last years of the study; the perinatal mortality rate dropped from 10.4% in 1965 to 1.6% in 1973 to 0% in 1974. This achievement reflects the significant progress in obstetrics that has been made during these years.

The regulatory nature of the phoB gene for alkaline phosphatase synthesis in Escherichia coli

Quantitative measurements of alkaline phosphatase activity in various merozygotic combinations and electrophoretic analyses of periplasmic proteins derepressed by phosphate-starvation show that phoB is a positive regulatory gene.

Control of proton translocation induced by ATPase activity in chloroplasts

1. Proton uptake was induced by ATP in the dark following light triggering of ATPase activity in chloroplasts. The accumulated protons were released when ATPase activity was inhibited by the energy transfer inhibitor DIO-9. 2. Approximately two protons were taken up for each ATP hydrolyzed at pH 8. A drop in H+/ATP ratio was caused by uncouplers such as NH4Cl and carbonyl cyanide p-trifluoromethoxyphenylhydrazone. These uncouplers caused an increase in the rate of ATP hydrolysis without a corresponding increase in proton uptake. 3. The energy transfer inhibitor dicyclocarbodiimide inhibited both ATPase activity and the rate of proton uptake without changing the H+/ATP ratio. 4. The antibiotic valinomycin caused an increase in the rate of both proton uptake and ATP hydrolysis without altering the ratio of H+/ATP. The H+/ATP ratio varied with changes in the external pH. The results were discussed in view of the chemiosmotic theory of oxidative and photosynthetic phosphorylation.