The relationship between the rate of entry of ioxynil and effects on photosynthesis in normal and drought-stressed Stellaria media

The entry of ¹⁴C-labelled ioxynil octanoate into leaves of Stellaria media has been measured for plants grown in dry or moist soil. Of the total herbicide applied, 1–3% entered the leaf by 24 h and 2–5% by 72 h after treatment. Entry into moist-grown plants proceeded at about twice the rate of that into drought-stressed plants. Despite the limited rate of entry, the inhibitory action of ioxynil octanoate on photosynthetic carbon dioxide exchange was rapid, inhibition within 24 h reaching 70–90% in moist-grown plants, and 30–70% in dry-grown plants. Plants grown under moisture stress contained greater concentrations of the pigments chlorophyll a, carotene and lutein (a xanthophyll) than did moist-grown plants, and ioxynil-induced breakdown of these pigments was more rapid in moist-grown plants. It is suggested that these factors contribute to the greater tolerance of drought-stressed S. media to applications of ioxynil octanoate. The importance of continuous measurements of herbicide action is discussed in relation to the value and interpretation of ¹⁴C uptake data.     

Monocytes/macrophages express chemokine receptor CCR9 in rheumatoid arthritis and CCL25 stimulates their differentiation

Introduction  

Monocytes/macrophages accumulate in the rheumatoid (RA) synovium where they play a central role in inflammation and joint destruction. Identification of molecules involved in their accumulation and differentiation is important to inform therapeutic strategies. This study investigated the expression and function of chemokine receptor CCR9 in the peripheral blood (PB) and synovium of RA, non-RA patients and healthy volunteers.     

PROVISION OF COMMUNITY‐WIDE BENEFITS IN PUBLIC HEALTH INTERVENTION RESEARCH: THE EXPERIENCE OF INVESTIGATORS CONDUCTING RESEARCH IN THE COMMUNITY SETTING IN SOUTH ASIA

Background: This article describes the types of community‐wide benefits provided by investigators conducting public health research in South Asia as well as their self‐reported reasons for providing such benefits. Methods: We conducted 52 in‐depth interviews to explore how public health investigators in low‐resource settings make decisions about the delivery of ancillary care to research subjects. In 39 of the interviews respondents described providing benefits to members of the community in which they conducted their study. We returned to our narrative dataset to find answers to two questions: What types of community‐wide benefits do researchers provide when conducting public health intervention studies in the community setting, and what reasons do researchers give when asked why they provided community‐wide benefits? Findings: The types of community‐wide benefits delivered were directed to the health and well‐being of the population. The most common types of benefits delivered were the facilitation of access to health care for individuals in acute medical need and emergency response to natural disasters. Respondents' self‐reported reasons when asked why they provided such benefits fell into 2 general categories: intrinsic importance and instrumental importance.     

Association of genetic variants rs641153 (CFB), rs2230199 (C3), and rs1410996 (CFH) with age-related macular degeneration in a Brazilian population

This study aimed to investigate the association among genetic variants of the complement pathway CFB R32Q (rs641153), C3 R102G (rs2230199), and CFH (rs1410996) with age-related macular degeneration (AMD) in a sample of the Brazilian population. In a case-control study, 484 AMD patients were classified according to the clinical age-related maculopathy grading system (CARMS) and compared to 479 unrelated controls. The genetic variants rs1410996 of complement H (CFH), rs641153 of complement factor B (CFB), and rs2230199 of complement 3 (C3) were evaluated through polymerase chain reaction (PCR) and direct sequencing. The associations between single nucleotide polymorphisms (SNPs) and AMD, adjusted by age, were assessed by using logistic regression models. A statistically significant association was observed between AMD risk and rs2230199 variant with an OR of 2.01 (P  = 0.0002) for CG individuals compared to CC individuals. Regarding the comparison of advanced AMD versus the control group, the OR was 2.12 (P = 0.0036) for GG versus AA genotypes for rs1410996 variant. Similarly, the OR for rs2230199 polymorphism was 2.3034 (P  = 5.47^e-05) when comparing CG individuals to CC carriers. In contrast, the rs641153 variant showed a significant protective effect against advanced AMD for GA versus GG genotype (OR = 0.4406; P  = 0.0019). When comparing wet AMD versus controls, a significant association was detected for rs1410996 variant (OR = 2.16; P  = 0.0039) comparing carriers of the homozygous GG versus AA genotype, as well as in the comparisons of GG (OR = 3.0713; P  = 0.0046) and CG genotypes (OR = 2.2249; P  = 0.0002) versus CC genotype for rs2230199 variant, respectively. The rs641153 variant granted a significant protective effect against wet AMD for GA versus GG genotypes (OR = 0.4601; P  = 0.0044). Our study confirmed the risk association between rs2230199 and rs1410996 variants and AMD, and the protective role against AMD for rs641153 variant.     

Growth of Anopheles mosquito larvae on dietary microbiota in aquatic surface microlayers

Abstract. Hydrophobic organic matter accumulates under the surface film of water bodies to form the surface microlayers. Heterotrophic microorganisms use this organic matter for growth, and they, in turn, are fed upon by Anopheles mosquito larvae and other animals. From laboratory experiments we show that two species of mosquito larvae, Anopheles gambiae and An.quadrimaculatus , grew most rapidly where surface micro-layers were present and, especially, where labile dissolved organic matter was added to promote growth of microorganisms. The importance of microorganisms was confirmed by the addition of gentamicin antibiotic, which suppressed the microbiota and reduced the growth of larvae feeding on surface microlayers. Anopheles larvae grew well on a suspension of finely ground fish food to which the antibiotic had been added, showing that reduced growth was not due to gentamicin itself. Because sub-surface microorganisms are the components of the larval diet that most affect growth, we discuss their relevance to strategies for larval control of Anopheles mosquitoes.     

Evidence for Close Linkage of Human Amylase Loci

HUMAN α-amylase (α-1,4-glucan 4-glucanohydrolase, E.C. 3.2.1.1) is primarily in the pancreas and salivary glands and can be detected in serum and urine (UAmy) as well as in saliva (SaAmy) and duodenal secretions. The SaAmy locus (Amy₁) has at least three mutant alleles with the combined frequency of electrophoretic variant phenotypes totalling approximately 0.01 in Caucasian Americans¹. Subsequently, UAmy was shown to be a convenient source of pancreatic amylase. The pancreatic amylase locus (Amy₂) has at least two mutant alleles in Caucasian and Afro-Americans². The variant UAmy Ss is common in Caucasians whereas UAmy Sp has been found only in Afro-Americans; the frequency of variant phenotypes is 0·086 in each population².