Distribution and movement of toxaphene in anaerobic saline marsh soils

The biological oxygen demand (BOD) of filtered water from Lake Wingra, Wisconsin is significantly higher in the littoral zone than in the pelagial zone. Laboratory experiments indicate that BOD is not influenced by water temperature at the time of sampling or by enrichment with nitrate or ammonia. Rather, enrichment with macrophyte leachate sharply increases BOD, and enrichment with phosphate produces a small but significant increase in BOD. We conclude that high BOD in littoral waters of the lake is an indication of production of labile organic matter in the water by dense beds of the macrophyte Myriophyllum spicatum.     

Effects of hyperthermia on the mouse testis and its response to X-rays, as assayed by weight loss.

The effects of both hyperthermia alone and X-rays combined with hyperthermia on mouse testis have been investigated. Testis weight on heating time was observed for temperatures in the range 39.5 to 43.75 degrees C. The relationship between the reaction rate and the reciprocal of absolute temperature indicated that, over the temperature range considered, the activation energy associated with such thermal damage was (646 +/- 45) x 10(3) J mol-1. No evidence was obtained to indicate a change in slope of the Arrhenius plot over this temperature range. Finally, despite the high sensitivity of the testis to heat and X-rays, no thermal enhancement of the weight loss after irradiation was observed when thermal treatments which, if given alone would produce some observable damage, were administered immediately after irradiation.     

Production and characterization of antisera against three individual NHC proteins; a case of a generally distributed NHC protein

In order to assess the selectivity of the distribution patterns of individual nonhistone chromosomal proteins (NHC proteins), immunofluorescent staining experiments were performed on Drosophila polytene chromosomes. Antisera have been prepared against three individual NHC proteins which were isolated by sequential preparative slab gel isoelectric focusing and SDS polyacrylamide gel electrophoresis. In two cases, immunofluorescent staining of the chromosomes indicated a specific limited distribution pattern; apparently the antigen in each case is present at a reproducible and distinct subset of chromomeres. This type of pattern has also been obtained with antisera prepared against molecular weight subfractions of NHC proteins (Silver and Elgin, 1977). Each selective fluorescence distribution pattern obtained so far is reproducible and unique to the antiserum under study. In a third case, an antiserum caused prominant staining at dense chromomeres and the chromocenter in a pattern mimicking DNA (and presumably histone) distribution. Indirect radioimmunostaining of SDS and isoelectric focusing gels on which total NHC proteins had been separated confirmed that this antiserum reacted specifically with a protein(s) of molecular weight 21,000 D and pI 5.2. The data in conjunction with absorption experiments indicates that the chromosomal staining is due to an interaction of antibodies with NHC protein(s) and not with histones. This finding suggests that at least one major acidic NHC protein plays a very general role (comparable to that of the histones) in maintaining chromatin structure.     

A requirement for cytoplasmic protein synthesis during chloroplast senescence in the aquatic plant Anacharis canadensis

Cycloheximide (CHI) at 1 µg/liter delayed the loss ofchlorophyll from detached Anacharis canadensis leaflets senescingin the dark. Chloramphenicol (CAP) and streptomycin (SM) slightlyaccelerated the loss. CHI was effective even during the laterstages of senescence in preventing further loss of chlorophyll.Senescence proceeded normally upon return of the leaflets intowater. The need for cytoplasmic protein synthesis during chloroplastsenescence and the types of proteins involved are discussed. (Received March 26, 1976; )     

The proteins of polytene chromosomes of Drosophila hydei

It is reported that chromatin can be prepared from highly purified polytene nuclei from the salivary glands of third instar larvae of Drosophila hydei; such chromatin differs from that of diploid nuclei mainly by deficiencies in certain nonhistone chromosomal proteins. It is suggested that these proteins are important components of constitutive heterochromatin, which is severely underrepresented in polytene chromosomes. Chromosome morphology, including the pattern of induced puffs, is maintained throughout the mass isolation of glands and sucrose gradient purification of nuclei, as indicated by studies on temperature-shocked and control larvae. No significant alteration in the chromosomal proteins following puff induction by heat shock could be detected on analysis of the isolated protein fractions by disc gel electrophoresis. More sensitive techniques must be developed to study the apparent rearrangement or accumulation of protein at puff sites, and to elucidate the role of this protein in gene activation.     

The cardioregulatory system of crayfish: neuroanatomy and physiology.

1. The anatomical arrangement of the cardioregulatory nerves and their physiological activity during cardiac modulation were analysed in Procambarus clarkii. 2. The bilaterally arranged pairs of cardioinhibitors and cardioaccelerator axons, in nerves SN II and SN III respectively, were physiologically identified by correlating spikes in SN II and SN III with the same spikes in the dorsal nerve, which innervates the heart. 3. The cardioinhibitor neurone fired tonically in varied sporadic bursts. During periods of cardiac inhibition, however, this neurone discharged in a long chain of spikes at a characteristic frequency of 40-50Hz. 4. The cardioaccelerator neurone fired tonically at 2-3 Hz but on occasion its activity reached 12 Hz. 5. Three inhibitory cardiac reflexes were analysed. The sensory modalities for the reflexes included (a) stretch of the dorsal pericardial wall, (b) chemical stimulation of coxal hair sensilla with glucose and (c) tactile stimulation of hair sensilla in and below the gill chamber, on the antennae, the antennules and on the anterior cephalothorax. 6. The discharge of both cardioinhibitor neurones showed a weak temporal correlation suggesting a common presynaptic drive, while the pair of cardioaccelerators appeared to have a reciprocal relationship with the cardioinhibitors.     

The temperature dependences of some types of gaseous ionic reactions of astrochemical interest

The rate constants of ion-molecule reactions which are of potential significance in astrochemical systems are found to exhibit significant, and in many cases, negative temperature dependences. The rate constants of fast ion-polar molecule reactions (e.g., XH⁺+B»BH⁺+X) may increase by a factor of 5–10 between 1000 and 10K. Slow reactions that proceed via reaction complexes (e.g., H-transfer and association reactions) often exhibit temperature dependences of the formk=AT ⁻ⁿ ,n=1–5. Both transition state theory considerations and the coupled-oscillator RRK-type model are seen to be able to account qualitatively for the behavior of slow ion-molecule, reactions.     

Pyronaridine–artesunate real-world safety,tolerability, and effectiveness in malaria patients in 5 African countries: A single-arm,open-label,cohort event monitoring study

BackgroundIn Phase II/III randomized controlled clinical trials for the treatment of acute uncomplicated malaria, pyronaridine–artesunate demonstrated high efficacy and a safety profile consistent with that of comparators, except that asymptomatic, mainly mild-to-moderate transient increases in liver aminotransferases were reported for some patients. Hepatic safety, tolerability, and effectiveness have not been previously assessed under real-world conditions in Africa.Methods and findingsThis single-arm, open-label, cohort event monitoring study was conducted at 6 health centers in Cameroon, Democratic Republic of Congo, Gabon, Ivory Coast, and Republic of Congo between June 2017 and April 2019. The trial protocol as closely as possible resembled real-world clinical practice for the treatment of malaria at the centers. Eligible patients were adults or children of either sex, weighing at least 5 kg, with acute uncomplicated malaria who did not have contraindications for pyronaridine–artesunate treatment as per the summary of product characteristics. Patients received fixed-dose pyronaridine–artesunate once daily for 3 days, dosed by body weight, without regard to food intake. A tablet formulation was used in adults and adolescents and a pediatric granule formulation in children and infants under 20 kg body weight. The primary outcome was the hepatic event incidence, defined as the appearance of the clinical signs and symptoms of hepatotoxicity confirmed by a >2× rise in alanine aminotransferase/aspartate aminotransferase (ALT/AST) versus baseline in patients with baseline ALT/AST >2× the upper limit of normal (ULN). As a secondary outcome, this was assessed in patients with ALT/AST >2× ULN prior to treatment versus a matched cohort of patients with normal baseline ALT/AST. The safety population comprised 7,154 patients, of mean age 13.9 years (standard deviation (SD) 14.6), around half of whom were male (3,569 [49.9%]). Patients experienced 8,560 malaria episodes; 158 occurred in patients with baseline ALT/AST elevations >2×ULN. No protocol-defined hepatic events occurred following pyronaridine–artesunate treatment of malaria patients with or without baseline hepatic dysfunction. Thus, no cohort comparison could be undertaken. Also, as postbaseline clinical chemistry was only performed where clinically indicated, postbaseline ALT/AST levels were not systematically assessed for all patients. Adverse events of any cause occurred in 20.8% (1,490/7,154) of patients, most frequently pyrexia (5.1% [366/7,154]) and vomiting (4.2% [303/7,154]). Adjusting for Plasmodium falciparum reinfection, clinical effectiveness at day 28 was 98.6% ([7,369/7,746] 95% confidence interval (CI) 98.3 to 98.9) in the per-protocol population. There was no indication that comorbidities or malnutrition adversely affected outcomes. The key study limitation was that postbaseline clinical biochemistry was only evaluated when clinically indicated.ConclusionsPyronaridine–artesunate had good tolerability and effectiveness in a representative African population under conditions similar to everyday clinical practice. These findings support pyronaridine–artesunate as an operationally useful addition to the management of acute uncomplicated malaria.Trial registrationClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03201770","term_id":"NCT03201770"}}NCT03201770.

Gaston Tona Lutete and co-workers report on safety and effectiveness of the antimalarial drug pyronaridine-artesunate in African countries.