A Survey to Assess Family Physicians’ Motivation to Teach Undergraduates in Their Practices

Background

In Germany, family physicians (FPs) are increasingly needed to participate in undergraduate medical education. Knowledge of FPs’ motivation to teach medical students in their practices is lacking.

Purpose

To describe a novel questionnaire that assesses the motivation of FPs to teach undergraduates in their practices and to show the results of a subsequent survey using this instrument.

Methods

The questionnaire was developed based on a review of the literature. Previously used empirical instruments assessing occupational values and motivation were included. A preliminary version was pretested in a pilot study. The resulting 68-item questionnaire was sent to 691 FPs involved in undergraduate medical education. Reliability was assessed and subgroups were analyzed with regard to differences in motivation.

Results

A total of 523 physicians in n = 458 teaching practices participated (response rate 75.7%). ‘Helping others’ and ‘interest’ were revealed as the predominant motives. Responses showed a predominantly intrinsic motivation of the participating FPs. Their main incentives were an ambition to work as a medical preceptor, to generally improve undergraduate education and to share knowledge. Material compensation was of minor importance. Time restraints were indicated as a barrier by some FPs, but were not a general concern.

Conclusion

German FPs involved in medical education have altruistic attitudes towards teaching medical students in their practices. Motivational features give an important insight for the recruitment of FP preceptors as well as for their training in instructional methods.     

Do Zebra Finch Parents Fail to Recognise Their Own Offspring?

Individual recognition systems require the sender to be individually distinctive and the receiver to be able to perceive differences between individuals and react accordingly. Many studies have demonstrated that acoustic signals of almost any species contain individualized information. However, fewer studies have tested experimentally if those signals are used for individual recognition by potential receivers. While laboratory studies using zebra finches have shown that fledglings recognize their parents by their "distance call", mutual recognition using the same call type has not been demonstrated yet. In a laboratory study with zebra finches, we first quantified between-individual acoustic variation in distance calls of fledglings. In a second step, we tested recognition of fledgling calls by parents using playback experiments. With a discriminant function analysis, we show that individuals are highly distinctive and most measured parameters show very high potential to encode for individuality. The response pattern of zebra finch parents shows that they do react to calls of fledglings, however they do not distinguish between own and unfamiliar offspring, despite individual distinctiveness. This finding is interesting in light of the observation of a high percentage of misdirected feedings in our communal breeding aviaries. Our results demonstrate the importance of adopting a receiver's perspective and suggest that variation in fledgling contact calls might not be used in individual recognition of offspring.     

Procoagulant Platelets Form an α-Granule Protein-covered “Cap” on Their Surface That Promotes Their Attachment to Aggregates

Strongly activated “coated” platelets are characterized by increased phosphatidylserine (PS) surface expression, α-granule protein retention, and lack of active integrin α_IIbβ₃. To study how they are incorporated into thrombi despite a lack of free activated integrin, we investigated the structure, function, and formation of the α-granule protein “coat.” Confocal microscopy revealed that fibrin(ogen) and thrombospondin colocalized as “cap,” a single patch on the PS-positive platelet surface. In aggregates, the cap was located at the point of attachment of the PS-positive platelets. Without fibrin(ogen) retention, their ability to be incorporated in aggregates was drastically reduced. The surface fibrin(ogen) was strongly decreased in the presence of a fibrin polymerization inhibitor GPRP and also in platelets from a patient with dysfibrinogenemia and a fibrinogen polymerization defect. In contrast, a fibrinogen-clotting protease ancistron increased the amount of fibrin(ogen) and thrombospondin on the surface of the PS-positive platelets stimulated with collagen-related peptide. Transglutaminases are also involved in fibrin(ogen) retention. However, platelets from patients with factor XIII deficiency had normal retention, and a pan-transglutaminase inhibitor T101 had only a modest inhibitory effect. Fibrin(ogen) retention was normal in Bernard-Soulier syndrome and kindlin-3 deficiency, but not in Glanzmann thrombasthenia lacking the platelet pool of fibrinogen and α_IIbβ₃. These data show that the fibrin(ogen)-covered cap, predominantly formed as a result of fibrin polymerization, is a critical mechanism that allows coated (or rather “capped”) platelets to become incorporated into thrombi despite their lack of active integrins.     

Do Babies Resemble Their Fathers More Than Their Mothers? A Failure to Replicate Christenfeld and Hill (1995)

Contrary to Christenfeld and Hill (1995), we find that children aged 1, 3, and 5 do not appear to resemble their fathers significantly more than their mothers. We provide an explanation as to why this should be. In addition, we note that any father–child resemblance that does exist, although better than chance, is far from overwhelming.     

Are Female Starlings Able to Recognize the Scent of Their Offspring?

Background

Although there is growing evidence that birds may have individual chemical profiles that can function in several social contexts, offspring recognition based on olfactory cues has never been explored. This ability should be more likely evolved in colonial birds and/or species suffering brood parasitism, in which the risk of being engaged in costly misdirected parental care is high.

Methodology/Principal Findings

We performed a choice experiment to examine whether females of the spotless starling, Sturnus unicolor, a species that is colonial, and where a fraction of the population is exposed to intraspecific brood parasitism, can discriminate between the scent of their offspring and that of unrelated nestlings. We also explored whether the development of the uropygial gland secretion may play a role in such olfactory discrimination by performing the choice experiments to females rearing nestlings of two different ages, that is, without and with developed uropygial glands. Results showed that female starlings did not preferentially choose the scent of their offspring, independently of whether the gland of nestlings was developed or not.

Conclusions/Significance

Our results suggest that female starlings do not have or do not show the ability to distinguish their offspring based on olfaction, at least up to 12–14 days of nestling age. Further research is needed to examine whether odour-based discrimination may function when fledgling starlings leave the nest and the risk of costly misidentification is likely to increase.     

γ-Irradiation Damage to Liposomes Differing in Composition and Their Protection by Nitroxides

The present study aims to determine the effect of bilayer composition on oxidative damage and the protection against it in lipid multicomponent membranes. Irradiation damage in 200-nm liposomes and the protection provided by the nitroxide radicals, 2,2,6,6-tetramethylpiperidine-1-oxyl (Tempo) and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol) were assessed by monitoring several chemical and physical parameters. Liposomes were prepared in four different lipid compositions (mole ratios), DPPC:DPPG 10:1; DPPC:DPPG:cholesterol 10:1:4; EPC:EPG 10:1; and EPC:EPG:cholesterol 10:1:4, and γ-irradiated with a dose of 32 kGy. Lipid degradation was determined by HPLC and GC analyses, whereas size and differential scanning calorimetry measurements were used to monitor physical changes in the liposomal dispersions. The results indicate that: (1) addition of 5 mM Tempo or Tempol, or freezing of the sample inhibited radiation-induced lipid degradation; (2) Tempo and Tempol caused neither physical nor chemical changes in the liposomal dispersions; and (3) both nitroxides prevented or reduced some of the radiation-induced changes in thermotropic characteristics of the liposomes, preventing a shift in the temperature of the maximum of the main phase transition (T_m).     

Olfactory Ensheathing Cells Express α7 Integrin to Mediate Their Migration on Laminin

The unique glia located in the olfactory system, called olfactory ensheathing cells (OECs), are implicated as an attractive choice for transplantation therapy following spinal cord injury because of their pro-regenerative characteristics. Adult OECs are thought to improve functional recovery and regeneration after injury by secreting neurotrophic factors and making cell-to-cell contacts with regenerating processes, but the mechanisms are not well understood. We show first that α7 integrin, a laminin receptor, is highly expressed at the protein level by OECs throughout the olfactory system, i.e., in the olfactory mucosa, olfactory nerve, and olfactory nerve layer of the olfactory bulb. Then we asked if OECs use the α7 integrin receptor directly to promote neurite outgrowth on permissive and neutral substrates, in vitro. We co-cultured α7^+/+ and α7^lacZ/lacZ postnatal cerebral cortical neurons with α7^+/+ or α7^lacZ/lacZ OECs and found that genotype did not effect the ability of OECs to enhance neurite outgrowth by direct contact. Loss of α7 integrin did however significantly decrease the motility of adult OECs in transwell experiments. Twice as many α7^+/+ OECs migrated through laminin-coated transwells compared to α7^+/+ OECs on poly-L-lysine (PLL). This is in contrast to α7^lacZ/lacZ OECs, which showed no migratory preference for laminin substrate over PLL. These results demonstrate that OECs express α7 integrin, and that laminin and its α7 integrin receptor contribute to adult OEC migration in vitro and perhaps also in vivo.     

Bryophytes with asexual reproduction — Their ability to succeed in an industrial area

Summary The extent to which the distribution of liverwort and moss species in the industrial area around Duisburg (Federal Republic of Germany) is influenced by asexual reproduction is studied using distribution data. The research shows that neither the liverworts nor the mosses — except the genus Plagiothecium — are more successful in the area of concentrated industry when they are capable of asexual reproduction.     

When Do HIV-Infected Women Disclose Their HIV Status to Their Male Partner and Why? A Study in a PMTCT Programme,Abidjan

Background

In Africa, women tested for HIV during antenatal care are counselled to share with their partner their HIV test result and to encourage partners to undertake HIV testing. We investigate, among women tested for HIV within a prevention of mother-to-child transmission of HIV (PMTCT) programme, the key moments for disclosure of their own HIV status to their partner and the impact on partner HIV testing.

Methods and Findings

Within the Ditrame Plus PMTCT project in Abidjan, 546 HIV-positive and 393 HIV-negative women were tested during pregnancy and followed-up for two years after delivery. Circumstances, frequency, and determinants of disclosure to the male partner were estimated according to HIV status. The determinants of partner HIV testing were identified according to women''s HIV status. During the two-year follow-up, disclosure to the partner was reported by 96.7% of the HIV-negative women, compared to 46.2% of HIV-positive women (χ² = 265.2, degrees of freedom [df] = 1, p < 0.001). Among HIV-infected women, privileged circumstances for disclosure were just before delivery, during early weaning (at 4 mo to prevent HIV postnatal transmission), or upon resumption of sexual activity. Formula feeding by HIV-infected women increased the probability of disclosure (adjusted odds ratio 1.54, 95% confidence interval 1.04–2.27, Wald test = 4.649, df = 1, p = 0.031), whereas household factors such as having a co-spouse or living with family reduced the probability of disclosure. The proportion of male partners tested for HIV was 23.1% among HIV-positive women and 14.8% among HIV-negative women (χ² = 10.04, df = 1, p = 0.002). Partners of HIV-positive women who were informed of their wife''s HIV status were more likely to undertake HIV testing than those not informed (37.7% versus 10.5%, χ² = 56.36, df = 1, p < 0.001).

Conclusions

In PMTCT programmes, specific psychosocial counselling and support should be provided to women during the key moments of disclosure of HIV status to their partners (end of pregnancy, weaning, and resumption of sexual activity). This support could contribute to improving women''s adherence to the advice given to prevent postnatal and sexual HIV transmission.     

Are Drug Companies Living Up to Their Human Rights Responsibilities? The Merck Perspective

BACKGROUND TO THE DEBATE: The human rights responsibilities of drug companies have been considered for years by nongovernmental organizations, but were most sharply defined in a report by the UN Special Rapporteur on the right to health, submitted to the United Nations General Assembly in August 2008. The "Human Rights Guidelines for Pharmaceutical Companies in relation to Access to Medicines" include responsibilities for transparency, management, monitoring and accountability, pricing, and ethical marketing, and against lobbying for more protection in intellectual property laws, applying for patents for trivial modifications of existing medicines, inappropriate drug promotion, and excessive pricing. Two years after the release of the Guidelines, the PLoS Medicine Debate asks whether drug companies are living up to their human rights responsibilities. Sofia Gruskin and Zyde Raad from the Harvard School of Public Health say more assessment is needed of such responsibilities; Geralyn Ritter, Vice President of Global Public Policy and Corporate Responsibility at Merck & Co. argues that multiple stakeholders could do more to help States deliver the right to health; and Paul Hunt and Rajat Khosla introduce Mr. Hunt's work as the UN Special Rapporteur on the right to the highest attainable standard of health, regarding the human rights responsibilities of pharmaceutical companies and access to medicines.     

The Patterns of Secretory Structure and Their Relation to Hypericin Content in Hypericum

金丝桃属植物分泌结构的类型和金丝桃素含量的相关性 吕洪飞^1,2 沈宗根¹ 李景原¹ 胡正海^1**     

Are Drug Companies Living Up to Their Human Rights Responsibilities? Moving Toward Assessment

BACKGROUND TO THE DEBATE: The human rights responsibilities of drug companies have been considered for years by nongovernmental organizations, but were most sharply defined in a report by the UN Special Rapporteur on the right to health, submitted to the United Nations General Assembly in August 2008. The "Human Rights Guidelines for Pharmaceutical Companies in relation to Access to Medicines" include responsibilities for transparency, management, monitoring and accountability, pricing, and ethical marketing, and against lobbying for more protection in intellectual property laws, applying for patents for trivial modifications of existing medicines, inappropriate drug promotion, and excessive pricing. Two years after the release of the Guidelines, the PLoS Medicine Debate asks whether drug companies are living up to their human rights responsibilities. Sofia Gruskin and Zyde Raad from the Harvard School of Public Health say more assessment is needed of such responsibilities; Geralyn Ritter, Vice President of Global Public Policy and Corporate Responsibility at Merck & Co. argues that multiple stakeholders could do more to help States deliver the right to health; and Paul Hunt and Rajat Khosla introduce Mr. Hunt's work as the UN Special Rapporteur on the right to the highest attainable standard of health, regarding the human rights responsibilities of pharmaceutical companies and access to medicines.     

Prevalence of Endosymbionts in Bemisia tabaci Populations and Their In Vivo Sensitivity to Antibiotics

Bemisia tabaci can harbor both primary and secondary endosymbionts, and the specific endosymbionts can differ among different B. tabaci biotypes. This study determined (1) the prevalence of the primary endosymbiont Portiera aleyrodidarum and secondary endosymbionts Arsenophonus and Wolbachia in two invasive biotypes (B and Q) and one indigenous biotype (Cv) in China and (2) the in vivo effect of three antibiotics (tetracycline, ampicillin trihydrate, and rifampicin) against the endosymbionts; if an antibiotic substantially inhibits an endosymbiont, it could be used to determine the effect of that endosymbiont on B. tabaci. P. aleyrodidarum and Wolbachia were detected in all the three biotypes, while Arsenophonus was found only in the Q and Cv biotypes. P. aleyrodidarum was found in all tested individuals of the three biotypes. Infection rates of Wolbachia in the B, Cv, and Q biotypes were 58, 68, and 48%, respectively. The infection rate of Arsenophonus was 44% in the Q biotype but only 22% in the Cv biotype. The antibiotics failed to eliminate P. aleyrodidarum from any individual of the B, Cv, and Q biotypes but eliminated the secondary endosymbionts, Arsenophonus and Wolbachia, from 50 to 80% of the adult B. tabaci. The effect of the antibiotics depended on the species of endosymbiont, the antibiotic, the B. tabaci biotype, and various interactions between these factors. When used against Arsenophonus, the efficiency of rifampicin was better than ampicillin and tetracycline, regardless of B. tabaci biotype. When inactivating Wolbachia in Cv and Q biotypes, the efficiency tetracycline was better than ampicillin and rifampicin, and while the efficiency of tetracycline was better than rifampicin and ampicillin when they were used against Wolbachia in B biotype.     

Secretory Structures and Their Relationship to Accumulation of Camptothecin in Camptotheca acuminata （Nyssaceae）

Camptotheca acuminata Decne. (Nyssaceae) is a major source of the anticancer camptothecin (CPT). It is important to understand how CPT accumulates in C.acuminata in order to improve CPT production strategies. The aim of this study was to anatomically and morphologically characterize the secretory structure in leaves and stems of C.acuminata and determine their relationship to accumulation of OPT. Secretory canals and glandular trichomes were found in young stems and young leaves. Secretory canals consisted of a sub-epidermal canal delimited by one to two layers of cells. Glandular trichomes were unicellular. Fluorescence microscopy and OPT analysis showed that OPT was primarily accumulated in secretory canals and glandular trichomes of leaves and stems.     

Binding Modes of Phthalocyanines to Amyloid β Peptide and Their Effects on Amyloid Fibril Formation

The inherent tendency of proteins to convert from their native states into amyloid aggregates is associated with a range of human disorders, including Alzheimer’s and Parkinson’s diseases. In that sense, the use of small molecules as probes for the structural and toxic mechanism related to amyloid aggregation has become an active area of research. Compared with other compounds, the structural and molecular basis behind the inhibitory interaction of phthalocyanine tetrasulfonate (PcTS) with proteins such as αS and tau has been well established, contributing to a better understanding of the amyloid aggregation process in these proteins. We present here the structural characterization of the binding of PcTS and its Cu(II) and Zn(II)-loaded forms to the amyloid β-peptide (Aβ) and the impact of these interactions on the peptide amyloid fibril assembly. Elucidation of the PcTS binding modes to Aβ₄₀ revealed the involvement of specific aromatic and hydrophobic interactions in the formation of the Aβ₄₀-PcTS complex, ascribed to a binding mode in which the planarity and hydrophobicity of the aromatic ring system in the phthalocyanine act as main structural determinants for the interaction. Our results demonstrated that formation of the Aβ₄₀-PcTS complex does not interfere with the progression of the peptide toward the formation of amyloid fibrils. On the other hand, conjugation of Zn(II) but not Cu(II) at the center of the PcTS macrocyclic ring modified substantially the binding profile of this phthalocyanine to Aβ₄₀ and became crucial to reverse the effects of metal-free PcTS on the fibril assembly of the peptide. Overall, our results provide a firm basis to understand the structural rules directing phthalocyanine-protein interactions and their implications on the amyloid fibril assembly of the target proteins; in particular, our results contradict the hypothesis that PcTS might have similar mechanisms of action in slowing the formation of a variety of pathological aggregates.     

Are Eating Occasions and Their Energy Content Related to Child Overweight and Socioeconomic Status?

The objectives of this study were: (i) to assess the relationships between childhood overweight (OW) and four eating behaviors: daily eating frequency, and the relative contribution of breakfast, main meals (lunch and dinner), and snacks to total daily energy intake (EI); (ii) to explore whether these eating behaviors are involved in the negative association between socioeconomic status (SES) and OW. A representative sample of French children aged 3-11 years (n = 748) was taken from the 1998-1999 cross-sectional French INCA1 (Enquête Individuelle et Nationale sur les Consommations Alimentaires) food consumption survey. Food intake was reported in a 7-day food record, and SES, physical activity, sedentary behavior (SED), weight, and height were reported by answering face-to-face questionnaires. After adjusting for EI, physical activity, and SED, OW was positively associated with the contribution of the main meals to EI (P = 0.03), not significantly associated with the contribution of breakfast to EI, and inversely correlated to the number of eating episodes (P = 0.009) and to the contribution of snacking episodes to EI (P = 0.007). Our data suggest that a combination of more frequent intake occasions and lower contribution of the main meals to total daily EI is associated with a smaller risk of OW in children. However, eating frequency was the only eating behavior that played a slight mediation role (contributing approximately 8%) in the inverse relationship between SES and OW.     

A Click Approach to Novel D-Ring-Substituted 16α-Triazolylestrone Derivatives and Characterization of Their Antiproliferative Properties

A simple and efficient synthesis of novel, D-ring substituted estrone derivatives containing a 16α-triazolyl moiety is described. Two epimeric azido alcohols (16α-azido-17α-hydroxy and 16α-azido-17β-hydroxy) of estra-1,3,5(10)-triene-3-methyl ether were prepared, followed by copper(I)-catalyzed azide-alkyne cycloaddition with various terminal alkynes. The steroidal triazoles were obtained in high yields and their activities against three human cancer cell lines (HeLa, MCF7 and A431) were screened. The most effective analogs were submitted to additional experiments in order to characterize their antiproliferative properties. As evidenced by flow cytometry, the selected steroids induced a disturbance in the HeLa cell cycle in a concentration- and exposure-dependent manner, through an increase of the hypodiploid population (subG1) and a cell cycle arrest in the G2/M phase. A noncancerous human fibroblast cell line (MRC5) was used to determine the selectivities of these compounds. Fluorescent microscopy after Hoechst 33258 - propidium iodide (HOPI) double staining revealed nuclear condensation and disturbed cell membrane integrity. The enhanced activities of caspase-3 and caspase-9 without activation of caspase-8 in the treated cells indicated the activation of the intrinsic pathway of apoptosis. The levels of cell cycle regulators (CDK1, cyclin B1/B2 and cdc25B) were decreased and the ratio Bax/Bcl-2 was increased 24 h after the treatment of HeLa cells (determined at an mRNA level by means of an RT-PCR technique). Under the same conditions, two agents elicited substantially increased degrees of phosphorylation of stathmin, as evidenced by Western blotting. The presented results demonstrate that these steroids can be regarded as appropriate structural scaffolds for the design and synthesis of further steroid analogs as innovative drug candidates with good efficacy.     

Neural Differentiation of Mesenchymal Stem Cells Influences Their Chemotactic Responses to Stromal Cell-Derived Factor-1α

Mesenchymal stem cells (MSCs) are proposed as a promising source for cell-based therapies in neural disease. Although increasing numbers of studies have been devoted to the delineation of factors involved in the migration of MSCs, the relationship between the chemotactic response and the differentiation status of these cells is still unclear. In the present study, we demonstrated that MSCs in varying neural differentiation states display various chemotactic responses to stromal cell-derived factor-1α (SDF-1α). The chemotactic responses of MSCs under different differentiation stages in response to SDF-1α were analyzed by Boyden chamber, and the results showed that cells of undifferentiation, 24-h preinduction, 5-h induction, and 18-h maintenance states displayed a stronger chemotactic response to SDF-1α, while 48-h maintenance did not. Further, we found that the phosphorylation levels of PI3K/Akt, ERK1/2, SAPK/JNK, and p38MAPK are closely related to the differentiation states of MSCs subjected to SDF-1α, and finally, inhibition of SAPK/JNK signaling significantly attenuates SDF-1α-stimulated transfilter migration of MSCs of undifferentiation, 24-h preinduction, 18-h maintenance, and 48-h maintenance, but not MSCs of 5-h induction. Meanwhile, interference with PI3K/Akt, p38MAPK, or ERK1/2 signaling prevents only cells at certain differentiation state from migrating in response to SDF-1α. Collectively, these results demonstrate that MSCs in varying neural differentiation states have different migratory capacities, thereby illuminating optimization of the therapeutic potential of MSCs to be used for neural regeneration after injury.