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.     

Bone formation rather than inflammation reflects Ankylosing Spondylitis activity on PET-CT: a pilot study

Introduction

Positron Emission Tomography - Computer Tomography (PET-CT) is an interesting imaging technique to visualize Ankylosing Spondylitis (AS) activity using specific PET tracers. Previous studies have shown that the PET tracers [¹⁸F]FDG and [¹¹C](R)PK11195 can target inflammation (synovitis) in rheumatoid arthritis (RA) and may therefore be useful in AS. Another interesting tracer for AS is [¹⁸F]Fluoride, which targets bone formation. In a pilot setting, the potential of PET-CT in imaging AS activity was tested using different tracers, with Magnetic Resonance Imaging (MRI) and conventional radiographs as reference.

Methods

In a stepwise approach different PET tracers were investigated. First, whole body [¹⁸F]FDG and [¹¹C](R)PK11195 PET-CT scans were obtained of ten AS patients fulfilling the modified New York criteria. According to the BASDAI five of these patients had low and five had high disease activity. Secondly, an extra PET-CT scan using [¹⁸F]Fluoride was made of two additional AS patients with high disease activity. MRI scans of the total spine and sacroiliac joints were performed, and conventional radiographs of the total spine and sacroiliac joints were available for all patients. Scans and radiographs were visually scored by two observers blinded for clinical data.

Results

No increased [¹⁸F]FDG and [¹¹C](R)PK11195 uptake was noticed on PET-CT scans of the first 10 patients. In contrast, MRI demonstrated a total of five bone edema lesions in three out of 10 patients. In the two additional AS patients scanned with [¹⁸F]Fluoride PET-CT, [¹⁸F]Fluoride depicted 17 regions with increased uptake in both vertebral column and sacroiliac joints. In contrast, [¹⁸F]FDG depicted only three lesions, with an uptake of five times lower compared to [¹⁸F]Fluoride, and again no [¹¹C](R)PK11195 positive lesions were found. In these two patients, MRI detected nine lesions and six out of nine matched with the anatomical position of [¹⁸F]Fluoride uptake. Conventional radiographs showed structural bony changes in 11 out of 17 [¹⁸F]Fluoride PET positive lesions.

Conclusions

Our PET-CT data suggest that AS activity is reflected by bone activity (formation) rather than inflammation. The results also show the potential value of PET-CT for imaging AS activity using the bone tracer [¹⁸F]Fluoride. In contrast to active RA, inflammation tracers [¹⁸F]FDG and [¹¹C](R)PK11195 appeared to be less useful for AS imaging.     

A calcium-binding sialoglycoprotein associated with an apparent eggshell membrane of Globodera rostochiensis

Energy dispersive X-ray microanalysis has been used to study the binding of two inhibitors of hatching in Globodera rostochiensis, ruthenium red and lanthanum, to a calcium binding site on the eggshell. Eggs were treated with either buffered ruthenium red or buffer only, and the levels of ruthenium and calcium that could be detected from the surface of eggshells were measured before and after repeated etching in a plasma oven. Counts for ruthenium increased during etching to a maximum after 8–12 min, just before the eggshell was eroded from the juvenile. The calcium levels on eggshells binding ruthenium red were suppressed relative to those from buffer. Similar experiments with lanthanum showed a significant increase in this inhibitor after 10 min etching and an accompanying suppression of calcium levels. The nature of the binding site was probed by measuring ruthenium red binding after pretreatment with selected enzymes. A non-specific protease, pronase, reduced the subsequent binding of this inhibitor but the site was resistant to trypsin in the presence of calcium. Neuraminidase also had an effect suggesting that the protein is a sialoglycoprotein. Phospholipase A2 but not Phospholipase C influenced the subsequent binding of ruthenium red. Phospholipase A₂ caused a loss of hatching ability and the degradation of a phospholipid from the eggshell. Ruthenium red binding was also reduced by treatment of eggshells with detergents or sonication. Apparently a calcium-binding sialoglycoprotein forms part of the integral proteins of an eggshell membrane located on the inner surface of the eggshell.     

Studies on plant growth-regulating substances

3-(3,5-Dichlorophenoxy)butyric acid and 2-(3,5-dichlorophenoxy)ethylamine were both shown to exert pronounced dwarfing effects on tomato seedlings. Examination of extracts of the treated plants revealed the conversion of these compounds to 3,5-dichlorophenoxyacetic acid (3,5-D) and it is concluded that the physiological activity shown in each case depends on such a conversion to 3,5-D within the tissues.     

The development of silver scurf (Helminthosporium solani) disease of potato

The main source of inoculum of Helminthosporium solani was the seed tuber; the fungus was not detected in soils in which infected potatoes had been grown the previous year. Lesions spread rapidly on seed tubers after planting, so that within a few weeks the entire surface was covered. As lesions aged they lost the capacity to sporulate, so most inoculum was produced in the first few weeks after planting. Infection of progeny tubers was first detected at the heel (stolon attachment) end soon after their initiation. Once established, lesions spread slowly on the surface of progeny tubers when in the soil; more rapid spread took place during storage. Potatoes which seemed unaffected at lifting became diseased during storage.