Fetuin-A ({alpha}2HS-glycoprotein) is a major serum adhesive protein that mediates growth signaling in breast tumor cells

The identity of the cell adhesive factors in fetal bovine serum, commonly used to supplement growth media, remains a mystery due to the plethora of serum proteins. In the present analyses, we showed that fetuin-A, whose function in cellular attachment in tissue culture has been debated for many years, is indeed a major serum cell attachment factor particularly for tumor cells. We are able to report this because of a new purification strategy that has for the first time given us a homogeneous protein band in colloidal Coomassie-stained gels that retains biological activity. The tumor cells adhered to immobilized fetuin-A and not α(2)-macroglobulin, its major contaminant. The interaction of cells with fetuin-A was driven mainly by Ca(2+) ions, and cells growing in regular medium supplemented with fetal bovine serum were just as sensitive to loss of extracellular Ca(2+) ions as cells growing in fetuin-A. Fractionation of human serum revealed that cell attachment was confined to the fractions that had fetuin-A. Interestingly, the tumor cells also took up fetuin-A and secreted it back to the medium using an unknown mechanism that can be observed in live cells. The attachment of tumor cells to fetuin-A was accompanied by phosphatidylinositol 3-kinase/Akt activation that was down-regulated in cells that lack annexin-A6, one of the cell surface receptors for fetuin-A. Taken together, our data show the significance of fetuin-A in tumor cell growth mechanisms in vitro and open new research vistas for this protein.     

Performance of the tsetse fly Glossina pallidipes reared under simple laboratory conditions

A simple grass-thatched hut was used to rear Glossina pallidipes Austen. Constructed to allow free flow of air, the temperature and humidity inside correspond to that of the outside environment. Pupae used to start the colony were obtained from pregnant females from Lambwe Valley, Western Kenya. Nine day-old females were paired with 12 day-old males for 7 days after which they were separated.Colony performance was evaluated on the basis of female survival, number and weight of puparia produced, and mortality rates. The emergence rate of puparia weighing more than 30 mg was above 80%. Data on the performance of the colony between June 1985 and June 1986 are presented. We suggest that the simple nature of the rearing facility and its direct contact with the outside environment have facilitated the colonization of the flies.

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Résumé Une cage très simple, conçue pour assurer l'arrivé d'air, et le maintien de l'humidité et de loa température extérieure, a été employée pour conserver et élever G. pallidipes. Les pupes utilisées pour constituer la souche provenaient de Lambwe valley (ouest du Kénya). Des couples de femelles vieilles de 9 jours et de mâles de 12 jours ont été consitués, les sexes ont ensiute été séparés. La performance de la souche a été estimée en fonction de la survie des femelles et du nombre et du poids des pupes produites, et des taux de mortalité. Plus de 80% des pupes ont pesé 30 mg et plus, et le taux d'émergence a été de 80%. Les résultats fournis concernent les performances observées entre juin 1985 et juin 1986. Nous estimons que la simplicité du dispositif d'élevage et le contact direct avec les conditions écologiques externes ont facilité l'éstablissement de la souche.

     

Use of Population-based Surveillance to Define the High Incidence of Shigellosis in an Urban Slum in Nairobi,Kenya

Background

Worldwide, Shigella causes an estimated 160 million infections and >1 million deaths annually. However, limited incidence data are available from African urban slums. We investigated the epidemiology of shigellosis and drug susceptibility patterns within a densely populated urban settlement in Nairobi, Kenya through population-based surveillance.

Methods

Surveillance participants were interviewed in their homes every 2 weeks by community interviewers. Participants also had free access to a designated study clinic in the surveillance area where stool specimens were collected from patients with diarrhea (≥3 loose stools within 24 hours) or dysentery (≥1 stool with visible blood during previous 24 hours). We adjusted crude incidence rates for participants meeting stool collection criteria at household visits who reported visiting another clinic.

Results

Shigella species were isolated from 224 (23%) of 976 stool specimens. The overall adjusted incidence rate was 408/100,000 person years of observation (PYO) with highest rates among adults 34–49 years old (1,575/100,000 PYO). Isolates were: Shigella flexneri (64%), S. dysenteriae (11%), S. sonnei (9%), and S. boydii (5%). Over 90% of all Shigella isolates were resistant to trimethoprim-sulfamethoxazole and sulfisoxazole. Additional resistance included nalidixic acid (3%), ciprofloxacin (1%) and ceftriaxone (1%).

Conclusion

More than 1 of every 200 persons experience shigellosis each year in this Kenyan urban slum, yielding rates similar to those in some Asian countries. Provision of safe drinking water, improved sanitation, and hygiene in urban slums are needed to reduce disease burden, in addition to development of effective Shigella vaccines.     

Voulkensin C–E,new 11-oxocassane-type diterpenoids and a steroid glycoside from Caesalpinia volkensii stem bark and their antiplasmodial activities

A bioassay guided isolation of potential antimalarial molecules from the stem bark of Caesalpinia volkensii Harms (Fabaceae) achieved three new 11-oxocassane-type diterpenoids named voulkensin C (1), D (2) and E (3) together with one steroid glycoside named 3-O-[β-glucopyranosyl(1→2)-O-β-xylopyranosyl]-stigmasterol (4) and seven other known compounds including stigmasterol (5), β-sitosterol (6), oleanolic acid (7), 3-β-acetoxyolean-12-en-28-methyl ester (8), voucap-5-ol (9), caesadekarin C (10), deoxycaesaldekarin C (11). The structures of the new compounds were determined on the basis of extensive spectroscopic data (IR, MS, ¹H and ¹³C NMR and 2D NMR) analyses. The polar extracts revealed moderate to good antiplasmodial activities against chloquine-sensitive (D6) and -resistant strains (W2) of Plasmodium falciparum. Whereas the pure isolates exhibited limited to moderate antiplasmodial activities with compound 4 showing the highest antiplasmodial activities (IC₅₀ values of 4.44 ± 0.88 and 2.74 ± 1.10 μM against D6 and W2 strains, respectively). These results suggest a possible contribution of phytochemicals from C. volkensii stem bark towards inhibition of plasmodial parasites’ growth hence potential antimalarial.     

A Household Serosurvey to Estimate the Magnitude of a Dengue Outbreak in Mombasa,Kenya, 2013

Dengue appears to be endemic in Africa with a number of reported outbreaks. In February 2013, several individuals with dengue-like illnesses and negative malaria blood smears were identified in Mombasa, Kenya. Dengue was laboratory confirmed and an investigation was conducted to estimate the magnitude of local transmission including a serologic survey to determine incident dengue virus (DENV) infections. Consenting household members provided serum and were questioned regarding exposures and medical history. RT-PCR was used to identify current DENV infections and IgM anti-DENV ELISA to identify recent infections. Of 1,500 participants from 701 households, 210 (13%) had evidence of current or recent DENV infection. Among those infected, 93 (44%) reported fever in the past month. Most (68, 73%) febrile infected participants were seen by a clinician and all but one of 32 participants who reportedly received a diagnosis were clinically diagnosed as having malaria. Having open windows at night (OR = 2.3; CI: 1.1–4.8), not using daily mosquito repellent (OR = 1.6; CI: 1.0–2.8), and recent travel outside of Kenya (OR = 2.5; CI: 1.1–5.4) were associated with increased risk of DENV infection. This survey provided a robust measure of incident DENV infections in a setting where cases were often unrecognized and misdiagnosed.     

Longer-Term Follow-Up of Kenyan Men Circumcised Using the ShangRing Device

Objectives

To ascertain clinical sequelae, client satisfaction and sexual behavior 2+ years after male circumcision using the ShangRing device.

Methods

We enrolled 199 men from the Kenya sites (Homa Bay district) participating in a 2012 study of the ShangRing device used in routine male circumcision services (N = 552). We enrolled men who had had the ShangRing placed successfully, and over-sampled men who had had an adverse event and/or were HIV-positive during the field study. In the present study, each participant was examined and interviewed by a study clinician, and penile photographs were taken to document longer-term cosmetic results and any abnormal findings.

Results

194 men were included in the analysis. The mean and median times between circumcision and the longer-term follow-up visit in this study were 31.8 and 32 months, respectively. Four men (2.1%) had signs/symptoms of a sexually transmitted infection (STI). Virtually all (99.5%) of the men were very satisfied with the appearance of their circumcised penis, and all would recommend a ShangRing circumcision to friends or family members. The most prevalent reported advantage of the circumcision was the ease of bathing and enhanced cleanliness of the penis (75.8%). 94.3% of the men did not cite a single negative feature of their circumcision. 87.5% of men reported more sexual pleasure post-MC, the most common reason being more prolonged intercourse. The majority of men (52.6%) reported one sexual partner post-MC, but more than a quarter of the men (28.1%) reported an increased number of partners post-MC. Less than half of the men (44.3%) reported using condoms half of the time or more, but the great majority of condom users stated that condom use was much easier post-MC, and 76.9% of users said they used condoms more after circumcision than before.

Conclusions

This study supports the safety and acceptability of ShangRing male circumcision during 2–3 years of follow-up. It should allay worries that the ShangRing procedure could lead to delayed complications later than the observation period of most clinical studies.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01567436","term_id":"NCT01567436"}}NCT01567436     

Mating and oviposition behaviour in the legume pod borer, Maruca testulalis

Experiments were conducted outdoors and in the insect rearing laboratory at the International Institute of Tropical Agriculture (IITA) in Nigeria. Four or five nights pairing duration gave the highest mating percentage and oviposition by the pod borer. Direct observations on adult mating revealed that some males mated more than once. The majority of females mated only once. A one-to-one ratio (with 10 males: 10 females) gave the best results for mating and oviposition. Mating took place between 21.00 h and 05.00 h when temperature ranged between 20–25°C and rh over 80% with peak activity occurring between 02.00 and 03.00 h. Oviposition followed a similar trend to that observed for mating with an equal sex ratio (of 10 or more pairs per cage) giving the highest egg count. The average number of eggs laid was ca. 400 per female. These results show a much higher oviposition potential for Maruca testulalis than has been previously reported. The results are discussed with regard to the rearing of this species under laboratory conditions.

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Accouplement et comportement de ponte de Maruca testulalis

Résumé Tant de l'extérieur qu'au laboratoire (à l'IITA au Nigéria), la durée optimale de maintien des couples de M. testulalis Geyer (Lep. Pyralidae) pour obtenir l'accouplement et la ponte a été de 4 à 5 nuits, toutefois les meilleurs résultats ont été obtenus à l'extérieur. L'observation directe a révélé que contrairement aux femelles, les mâles peuvent copuler plus d'une fois. Le meilleur rapport sexuel pour obtenir l'accouplement et la ponte est 1/1 (10 mâles/10 femelles), suivi de près par un raport avec excédent de mâles. L'accouplement a lieu entre 21 h et 5 h quand la température est entre 20 et 30°C et HR supérieure à 80%; un pic est observé entre 2 et 3 h. La ponte présente la même tendance que l'accouplement, avec une production d'ufs plus élevée pour au moins 10 couples par cage. Le nombre moyen d'ufs par femelle est environ 400. Ces résultats sont supérieurs à ce qui avait été indiqué précédemment. La discussion porte sur les difficultés rencontrées pour élever cette espèce au laboratoire.

     

Calcium-mediated modulation of microtubule assembly in human breast epithelial cells

Summary Normal human breast epithelial cells obtained from a reduction mammoplasty (S130) have been maintained in culture for up to a year in Ham's F12:Dulbecco's medium, with 5% equine serum and a low calcium concentration (0.04 mM). These cells undergo senescence and terminal differentiation if they are switched to high Ca²⁺ medium (1.05 mM). To clarify the mechanism by which Ca²⁺ regulates the growth of these cells, we studied the role of tubulin assembly-disassembly and the morphologic changes subsequent to high Ca²⁺ switch. An early Passage (9) of S130 breast epithelial cells growing in low Ca²⁺ medium was analyzed. Of a total of 785 counted cells, 720 (92%) were rounded and 65 (8%) were flat, elongated, and fibroblastlike. When the cells were switched to high Ca²⁺ medium, out of 553 cells, only 111 (20%) were rounded and the remaining 442 (80%) were elongated and fibroblastlike. Immunocytochemical localization of tubulin, using the immunogold silver enhancement technique, showed that the majority of low Ca²⁺-grown cells did not display a network of tubulin fibers, whereas high Ca²⁺-grown cells revealed extensive cytoplasmic network of polymerized tubulin, which seemed to stretch out the cells. Experiments designed to determine the mechanisms of tubulin polymerization in these cells revealed that: a) Cells grown in high Ca²⁺ medium containing 0.1 mM colchicine had a reduced proportion of elongated cells; b) treatement of the cells with the calcium ionophore A23187 in low calcium medium resulted in an increase in the number of elongated cells which had more polymerized tubulin; and d) treatment of the cells with cyclic-AMP in low Ca²⁺ medium had no observable effect on cell morphology. These results indicate that high levels of Ca²⁺ either favor tubulin polymerization or stabilize the polymerized state. This research was supported by NCI grant CA-38921 from the National Cancer Institute, Bethesda, MD, and by an institutional grant from the United Foundation of Greater Detroit.     

Extracellular functions of galectin-3

Galectin-3 has been suspected of modulating cell to extracellular matrix interactions in a novel fashion ever since it was first described. However, the rapid accumulation of research data in just the last 8 years alone has completely changed our perspective of this multifunctional protein. Its chimeric nature (consists of carbohydrate recognition and collagen like domains) somehow makes it suited to interact with a plethora of interesting extracellular matrix proteins some of which might enable it to cross the plasma membrane despite its lack of appropriate signal peptides. It is now becoming established as a mediator of signal transduction events on the cell surface as well as a mediator of a variety of extra-cellular processes such as kidney development, angiogenesis, neuronal functions, tumor metastasis, autoimmune disorders, endocytosis and possibly exocytosis. Nevertheless, it still retains its unique position as a mediator/modulator of cell to extracellular matrix adhesive interactions. Cells, particularly epithelial cells which lack galectin-3 expression, interact poorly with their extracellular matrices. In some of these processes, it functions as a matricellular protein, displaying both pro- and anti-adhesive properties. Published in 2004.