Sartorial eloquence: does it exist in the paediatrician-patient relationship?

OBJECTIVE--To evaluate children''s and parents'' perceptions of hospital doctors'' attire. DESIGN--Questionnaire study asking children and parents to assign positive and negative attributes to five photographs of a male or female doctor dressed formally and informally. SETTING--Outpatient department, Children''s Hospital, Birmingham. SUBJECTS--203 consecutive child-parent pairs attending outpatient clinics over three months. MAIN OUTCOME MEASURES--Children''s and parents'' preferences, assessed by comparing proportions. RESULTS--70% (286/406) of children and parents rated doctors'' dress as important; more children rated it "very important" (27% (54/203) v 14% (29/203), P < 0.01, 95% confidence interval for difference 5% to 21%). Of the 99 children responding, 44 regarded the man in white coat as most competent (44% v 20% expected by chance, P < 0.01, 34% to 54%) and most concerned (32% v 20%, P < 0.01, 23% to 41%). Children also regarded the woman in white coat as most competent; however, male and female doctors in white coats rated lower for friendliness. Asians and regular surgical attenders preferred doctors in white coats. The man in polo shirt and trousers was rated as most friendly (40% v 20% expected by chance, P < 0.01, 30% to 50%) and most gentle (37% v 20%, P < 0.01, 27% to 46%). The woman in tee shirt and slacks also rated most friendly and gentle; however, both casually dressed doctors rated lower for competence. Parents preferred more casual dress but expressed preferences less strongly, and they poorly predicted which outfits their children preferred. CONCLUSIONS--Children regard formally dressed doctors as competent but not friendly; they regard casual dress as friendly but not competent.     

Complex I of Trypanosomatidae: does it exist?

The presence of complex I, or NADH dehydrogenase, in Trypanosomatidae is debated. Several subunits of complex I have been identified by biochemical studies, but the overall composition of the complex has remained elusive. Here, the authors review the present literature related to this mitochondrial activity and carry out a bioinformatic analysis to allow the prediction of the composition of a putative trypanosomatid complex I. The complex comprises at least 19 subunits and has a minimum mass of 660 kDa. It is larger than the corresponding bacterial enzyme but smaller than the typical mitochondrial enzyme of eukaryotes. All subunits known to be involved in electron transport are present, but the complex does not seem to be involved in energy transduction because four membrane subunits, normally encoded by the mitochondrial genome and supposed to be involved in proton extrusion, are missing.     

Specialist approach to childhood asthma: does it exist?

Twenty six paediatricians and 21 consultant physicians concerned in the care of children with asthma answered a postal questionnaire on various aspects of the management of asthma, attitudes to referral, and the nature of advice given to parents and children. The 47 specialists had considerable differences in opinion for more than half the questions, including the role of allergen skin tests and the use of "breathing exercises." In addition, the paediatricians disagreed with the responses of the non-paediatricians on common issues such as whether to use aminophylline suppositories and whether swimming helps children grow out of asthma. These results have disturbing implications for the advice that specialists give to general practitioners, children, and parents.     

First-phase insulin secretion: does it exist in real life? Considerations on shape and function

To fulfill its preeminent function of regulating glucose metabolism, insulin secretion must not only be quantitatively appropriate but also have qualitative, dynamic properties that optimize insulin action on target tissues. This review focuses on the importance of the first-phase insulin secretion to glucose metabolism and attempts to illustrate the relationships between the first-phase insulin response to an intravenous glucose challenge and the early insulin response following glucose ingestion. A clear-cut first phase occurs only when the beta-cell is exposed to a rapidly changing glucose stimulus, like the one induced by a brisk intravenous glucose administration. In contrast, peripheral insulin concentration following glucose ingestion does not bear any clear sign of biphasic shape. Coupling data from the literature with the results of a beta-cell model simulation, a close relationship between the first-phase insulin response to intravenous glucose and the early insulin response to glucose ingestion emerges. It appears that the same ability of the beta-cell to produce a pronounced first phase in response to an intravenous glucose challenge can generate a rapidly increasing early phase in response to the blood glucose profile following glucose ingestion. This early insulin response to glucose is enhanced by the concomitant action of incretins and neural responses to nutrient ingestion. Thus, under physiological circumstances, the key feature of the early insulin response seems to be the ability to generate a rapidly increasing insulin profile. This notion is corroborated by recent experimental evidence that the early insulin response, when assessed at the portal level with a frequent sampling, displays a pulsatile nature. Thus, even though the classical first phase does not exist under physiological conditions, the oscillatory behavior identified at the portal level does serve the purpose of rapidly exposing the liver to elevated insulin levels that, also in virtue of their up-and-down pattern, are particularly effective in restraining hepatic glucose production.     

Vertebrate hox temporal collinearity: does it exist and what is it’s function?

Hox temporal collinearity (TC) is a mysterious feature of embryogenesis. This article is opportune because of a recent challenge to TC’s existence This challenge is examined and the evidence that TC does exist is presented. Its function is discussed. Temporal collinearity is thought to be important because it lays the basis for Hox spatial collinearity and the vertebrate A-P axial pattern. The time-space translation mechanism whereby this occurs is examined.     

DMT1: which metals does it transport?

DMT1-Divalent Metal (Ion) Transporter 1 or SLC11A2/DCT1/Nramp2 - transports Fe2+ into the duodenum and out of the endosome during the transferrin cycle. DMTI also is important in non-transferrin bound iron uptake. It plays similar roles in Mn2+ trafficking. Voltage clamping showed that six other metals evoked currents, but it is unclear if these metals are substrates for DMT1. This report summarizes progress on which metals DMT1 transports, focusing on results from the authors' labs. We recently cloned 1A/+IRE and 2/-IRE DMT1 isoforms to generate HEK293 cell lines that express them in a tetracycline-inducible fashion, then compared induced expression to uninduced expression and to endogenous DMT1 expression. Induced expression increases approximately 50x over endogenous expression and approximately 10x over uninduced levels. Fe2+, Mn2+, Ni2+ and Cu1+ or Cu2+ are transported. We also explored competition between metal ions using this system because incorporation essentially represents DMT1 transport and find this order for transport affinity: Mn>?Cd>?Fe>Pb-Co-Ni>Zn. The effects of decreased DMT1 also could be examined. The Belgrade rat has diminished DMT1 function and thus provides ways of testing. A series of DNA constructs that generate siRNAs specific for DMT1 or certain DMT1 isoforms yield another way to test DMT1-based transport.     

Regeneration in the metazoans: why does it happen?

Why does regeneration occur? And why, when it manifests itself, does it do so in some but not all metazoan species? Hence, what are the permissive or inhibitory factors operating behind this phenomenon? When it comes to regeneration, many questions, such as these, remain unanswered. In fact, the problem of animal regeneration has withstood the probing of scientific inquiry for over 250 years and still awaits a satisfactory mechanistic explanation. In this essay, I will review the distribution and the modes of regeneration that are found in the different metazoan phyla. Also, I will re-examine ideas on its evolutionary origins, and discuss its possible relationship to both asexual reproduction and embryogenesis. This endeavor has two objectives. First, to bring forward an interpretation of regeneration which integrates evolutionary and developmental considerations into its discussion. And second, to suggest a comparative experimental approach to this problem that may bring us closer to understanding the molecular basis of this long-standing biological problem. BioEssays 22:578-590, 2000.     

Seed positioning in extruded pellets: does it matter?

Extruded pellets containing activated carbon (AC) can be used to sow native seeds while simultaneously applying herbicide to control invasive species. Incorporating AC in pellets has been demonstrated to protect native seeds; however, there may be unintended detrimental impacts to seedling emergence. We aimed to optimize seed position within pellets to maximize emergence and survival of the perennial shrub Jacksonia furcellata. Seeds were positioned at 2 mm (top), 6 mm (middle), and 12 mm (bottom) within pellets (with or without AC), sown on or below the soil surface, and compared to non-pelleted seeds sown under the soil surface in the equivalent positions (2, 6, and 12 mm depth). Trays were treated with a pre-emergent herbicide (Simazine) or left unsprayed. Emergence (without herbicide) was significantly higher from seeds positioned at the bottom of pellets without AC sown on the soil surface (70%), compared to non-pelleted seeds sown at the bottom (12 mm below the soil surface; 57%). However, emergence was inhibited when seeds were positioned in the middle (6 mm) of pellets with AC (32%). When treated with Simazine, survival was highest from seeds positioned at the bottom of pellets with AC (60%), compared to pellets without AC (15%) and non-pelleted seeds sown at the bottom (12 mm below the soil surface; 15%). Jacksonia furcellata seeds positioned at the bottom of pellets, sown on the soil surface, shows promise to minimize negative impacts to emergence, and maximize herbicide protection. Further testing with additional species is required to refine pellet production (e.g. recipe, extrusion, and shape) for optimal emergence.     

Vesicular transport in capillary endothelium: does it occur?

A revised picture of the organization of endothelial plasmalemmal vesicles is presented. Three-dimensional reconstructions of endothelial segments from frog mesenteric capillaries and rat heart capillaries based on ultrathin serial sectioning have shown that plasmalemmal vesicles are not true vesicles but parts of an elaborate system of invaginations of the surface membrane. The revised picture probably applies to capillary endothelia in general. The absence of free cytoplasmic vesicles implies that vesicular transport is unlikely to occur. A reinterpretation of previous studies of vesicular transport shows that they are equally compatible with the present view that plasmalemmal vesicles are static elements of invaginations of the endothelial surface membrane.     

Drug resistance in Leishmania: does it really matter?

Treatment failure (TF) jeopardizes the management of parasitic diseases, including leishmaniasis. From the parasite’s point of view, drug resistance (DR) is generally considered as central to TF. However, the link between TF and DR, as measured by in vitro drug susceptibility assays, is unclear, some studies revealing an association between treatment outcome and drug susceptibility, others not. Here we address three fundamental questions aiming to shed light on these ambiguities. First, are the right assays being used to measure DR? Second, are the parasites studied, which are generally those that adapt to in vitro culture, actually appropriate? Finally, are other parasite factors – such as the development of quiescent forms that are recalcitrant to drugs – responsible for TF without DR?     

Does F1-ATPase subunit gamma turn in the wrong direction?

Analyzing the direction of F1-ATPase subunit gamma rotation, its shape and non-random distribution of surface residues, a mechanism is proposed for how gamma induces the closing/opening of the catalytic sites at beta/alpha interfaces: by keeping contact with the mobile domain of subunits beta at the 'jaw' (D386, the seven consecutive hydrophobic residues and D394/E395), rotating gamma works as a screw conveyer within the barrel of (alpha,beta)3. Mutations of the conveyer contacts are predicted to inhibit. Rotating wheel cartoons illustrate enzyme turnover and conformational changes. Steric clashes, polar interactions and also substrate limitations lead to specific stops. Because it is constructed as a stepper, gamma prevents uncoupling at high energy charge.     

Subfunctionalization: How often does it occur? How long does it take?

The mechanisms responsible for the preservation of duplicate genes have been debated for more than 70 years. Recently, Lynch and Force have proposed a new explanation: subfunctionalization--after duplication the two gene copies specialize to perform complementary functions. We investigate the probability that subfunctionalization occurs, the amount of time after duplication that it takes for the outcome to be resolved, and the relationship of these quantities to the population size and mutation rates.     

Does F1-ATPase subunit γ turn in the wrong direction?

Analyzing the direction of F₁-ATPase subunit γ rotation, its shape and non-random distribution of surface residues, a mechanism is proposed for how γ induces the closing/opening of the catalytic sites at β/α interfaces: by keeping contact with the mobile domain of subunits β at the ‘jaw’ (D386, the seven consecutive hydrophobic residues and D394/E395), rotating γ works as a screw conveyer within the barrel of (α,β)₃. Mutations of the conveyer contacts are predicted to inhibit. Rotating wheel cartoons illustrate enzyme turnover and conformational changes. Steric clashes, polar interactions and also substrate limitations lead to specific stops. Because it is constructed as a stepper, γ prevents uncoupling at high energy charge.     

Symmetry breakage in the vertebrate embryo: When does it happen and how does it work?

Asymmetric development of the vertebrate embryo has fascinated embryologists for over a century. Much has been learned since the asymmetric Nodal signaling cascade in the left lateral plate mesoderm was detected, and began to be unraveled over the past decade or two. When and how symmetry is initially broken, however, has remained a matter of debate. Two essentially mutually exclusive models prevail. Cilia-driven leftward flow of extracellular fluids occurs in mammalian, fish and amphibian embryos. A great deal of experimental evidence indicates that this flow is indeed required for symmetry breaking. An alternative model has argued, however, that flow simply acts as an amplification step for early asymmetric cues generated by ion flux during the first cleavage divisions. In this review we critically evaluate the experimental basis of both models. Although a number of open questions persist, the available evidence is best compatible with flow-based symmetry breakage as the archetypical mode of symmetry breakage.     

Impact factor in cytopathology journals: what does it reflect and how much does it matter?

B. AbdullGaffar
Impact factor in cytopathology journals: what does it reflect and how much does it matter? Objective: To study the trends of impact factor (IF) in four cytopathology journals. To investigate the factors that might influence IF in cytopathology literature and whether IF has any impact on cytopathology practice. Methods: The IFs of four cytopathology journals were searched from 2005 to 2009. The IFs and their relationships with the types and number of publications, publishers, the official societies, readership, the quality of their contents, the topics covered and the levels of evidence were compared. Results: Cancer Cytopathology (CC) had the highest IF. Acta Cytologica (AC) had the lowest IF, which appeared to be in decline. Cytopathology (C) and Diagnostic Cytopathology (DC) had a slow but steady increase in their IF. Components that might influence these differences could include the category and the society of the journal, targeted readers and certain types of publications. Publishers, the number of publications, the types of topics covered and the levels of evidence probably have no major effect on IF. Conclusions: IF has its own benefits and original applications. IF is a quantitative measure that does not reflect the levels of evidence in cytopathology journals. IF should not be abandoned because it might encourage competition between cytopathology journals, but it should not dictate their contents.     

Apoptosis: why and how does it occur in biology?

The literature on apoptosis has grown tremendously in recent years, and the mechanisms that are involved in this programmed cell death pathway have been enlightened. It is now known that apoptosis takes place starting from early development to adult stage for the homeostasis of multicellular organisms, during disease development and in response to different stimuli in many different systems. In this review, we attempted to summarize the current knowledge on the circumstances and the mechanisms that lead to induction of apoptosis, while going over the molecular details of the modulator and mediators of apoptosis as well as drawing the lines between programmed and non-programmed cell death pathways. The review will particularly focus on Bcl-2 family proteins, the role of different caspases in the process of apoptosis, and their inhibitors as well as the importance of apoptosis during different disease states. Understanding the molecular mechanisms involved in apoptosis better will make a big impact on human diseases, particularly cancer, and its management in the clinics.