Pilot study: placental biomarker predictive capability (sFlt-1, PlGF and their ratio) of postpartum maternal outcome.

BACKGROUND: Prenatal measurement of placental biomarkers was able to improve screening and diagnosis of preeclampsia. Little is known about the clinical role of placental biomarkers in the postpartum period. METHODS: This study is a prospective monocentric trial that included a total of 30 women with preeclamptic pregnancies. Serum placental biomarkers including soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) were measured before and 2 h after delivery by Enzyme-Linked Immunosorbent Assay (ELISA) using commercially available kits according to manufacturer's instructions and correlated with the postpartum outcome. RESULTS: Postpartum higher serum PlGF level was associated with postpartum elevation of the systolic blood pressure. Yet, the placental biomarkers were not able to predict general worsening of postpartum preeclampsia or other individual clinical or laboratory parameters. CONCLUSION: Serum concentrations of sFlt-1 and PlGF or their ratio in our study cohort did not completely predict the occurrence of postpartum preeclampsia. Yet, postpartum higher serum PlGF level was associated with postpartum elevation of the systolic blood pressure.

Use of quantum effects as potential qualifying metrics for "quantum grade silicon".

Across solid state quantum information, materials deficiencies limit performance through enhanced relaxation, charge defect motion or isotopic spin noise. While classical measurements of device performance provide cursory guidance, specific qualifying metrics and measurements applicable to quantum devices are needed. For quantum applications, new materials metrics, e.g., enrichment, are needed, while existing, classical metrics like mobility might be relaxed compared to conventional electronics. In this work, we examine locally grown silicon superior in enrichment, but inferior in chemical purity compared to commercial-silicon, as part of an effort to underpin the materials standards needed for quantum grade silicon and establish a standard approach for intercomparison of these materials. We use a custom, mass-selected ion beam deposition technique, which has produced isotopic enrichment levels up to 99.99998 % 28Si, to isotopically enrich 28Si, but with chemical purity > 99.97% due the MBE techniques used. From this epitaxial silicon, we fabricate top-gated Hall bar devices simultaneously on the 28Si and on the adjacent natural abundance Si substrate for intercomparison. Using standard-methods, we measure maximum mobilities of ≈(1740±2)cm2/(V⋅s) at an electron density of (2.7×1012±3×108) cm-2 and ≈(6040±3)cm2/(V⋅s) at an electron density of (1.2×1012±5×108) cm-2 at T=1.9 K for devices fabricated on 28Si and natSi, respectively. For magnetic fields B>2 T, both devices demonstrate well developed Shubnikov-de Haas (SdH) oscillations in the longitudinal magnetoresistance. This provides transport characteristics of isotopically enriched 28Si, and will serve as a benchmark for classical transport of 28Si at its current state, and low temperature, epitaxially grown Si for quantum devices more generally.

What causes mating system shifts in plants? Arabidopsis lyrata as a case study.

The genetic breakdown of self-incompatibility (SI) and subsequent mating system shifts to inbreeding has intrigued evolutionary geneticists for decades. Most of our knowledge is derived from interspecific comparisons between inbreeding species and their outcrossing relatives, where inferences may be confounded by secondary mutations that arose after the initial loss of SI. Here, we study an intraspecific breakdown of SI and its consequences in North American Arabidopsis lyrata to test whether: (1) particular S-locus haplotypes are associated with the loss of SI and/or the shift to inbreeding; (2) a population bottleneck may have played a role in driving the transition to inbreeding; and (3) the mutation(s) underlying the loss of SI are likely to have occurred at the S-locus. Combining multiple approaches for genotyping, we found that outcrossing populations on average harbour 5 to 9 S-locus receptor kinase (SRK) alleles, but only two, S1 and S19, are shared by most inbreeding populations. Self-compatibility (SC) behaved genetically as a recessive trait, as expected from a loss-of-function mutation. Bulked segregant analysis in SC × SI F2 individuals using deep sequencing confirmed that all SC plants were S1 homozygotes but not all S1 homozygotes were SC. This was also revealed in population surveys, where only a few S1 homozygotes were SC. Together with crossing data, this suggests that there is a recessive factor that causes SC that is physically unlinked to the S-locus. Overall, our results emphasise the value of combining classical genetics with advanced sequencing approaches to resolve long outstanding questions in evolutionary biology.

Diet and cancer.

Large claims have been made for the effectiveness of particular diets in preventing cancer or inhibiting its progression. However, more recent clinical studies have not confirmed this. Instead it seems that rather than specific dietary constituents, total calories influence cancer incidence and progression. In this review article, we summarise and interpret the available evidence for links between diet and cancer.

Focal motility determines the geometry of dendritic spines.

The geometry of dendritic spines has a major impact on signal transmission at excitatory synapses. To study it in detail we raised transgenic mice expressing an intrinsic green fluorescent protein-based plasma membrane marker that directly visualizes the cell surface of living neurons throughout the brain. Confocal imaging of developing hippocampal slices showed that as dendrites mature they switch from producing labile filopodia and polymorphic spine precursors to dendritic spines with morphologies similar to those reported from studies of adult brain. In images of live dendrites these mature spines are fundamentally stable structures, but retain morphological plasticity in the form of actin-rich lamellipodia at the tips of spine heads. In live mature dendrites up to 50% of spines had cup-shaped heads with prominent terminal lamellipodia whose motility produced constant alterations in the detailed geometry of the synaptic contact zone. The partial enveloping of presynaptic terminals by these cup-shaped spines coupled with rapid actin-driven changes in their shape may operate to fine-tune receptor distribution and neurotransmitter cross-talk at excitatory synapses.

Human CLP36, a PDZ-domain and LIM-domain protein, binds to alpha-actinin-1 and associates with actin filaments and stress fibers in activated platelets and endothelial cells.

A 38-kd protein that associates with F-actin structures in activated platelets and endothelial cells was purified, cloned, and characterized. The protein contains an N-terminal PDZ motif, a large intervening sequence, and a C-terminal LIM domain and was identified as the human homolog of rat CLP36. The study showed that CLP36 associates with actin filaments and stress fibers that are formed during shape change and spreading of platelets and during migration and contraction of endothelial cells. CLP36 binds to alpha-actinin-1 as shown by coimmunoprecipitation, pull-down experiments, yeast 2-hybrid analysis, and blot overlay assays and colocalizes with alpha-actinin-1 along endothelial actin stress fibers. In contrast to alpha-actinin-1, CLP36 was absent from focal adhesions in both activated platelets and endothelial cells. The N-terminal part of CLP36 containing the PDZ domain and the intervening region, but not the LIM domain, targeted enhanced green fluorescent protein fusion proteins to stress fibers in endothelial cells. Yeast 2-hybrid analysis demonstrated that the intervening sequence, but not the PDZ or the LIM domain of CLP36, binds to the spectrinlike repeats 2 and 3 of alpha-actinin-1. The study further shows that CLP36 binds to alpha-actinin in resting platelets and translocates as a CLP36/alpha-actinin complex to the newly formed actin cytoskeleton in activated platelets. The results indicate that CLP36 binds via alpha-actinin-1 to actin filaments and stress fibers in activated human platelets and endothelial cells. The study suggests that CLP36 may direct alpha-actinin-1 to specific actin structures and at this position might modulate the function of alpha-actinin-1. (Blood. 2000;96:4236-4245)

Structure and function of the C-terminal hypervariable region of K-Ras4B in plasma membrane targetting and transformation.

The C-terminal hypervariable domain of K-Ras4B targets the protein to the plasma membrane by a combination of positive charge and a hydrophobic signal (farnesyl group). We analysed the contribution of several structural features of the domain: net charge, charge distribution, amino acid sequence and lipid specificity to membrane targetting and function by using artificial 'hypervariable' domains fused to either EGFP or V12KRas4B. We found that charge and a lipid residue are sufficient for plasma membrane localization and function of the constitutively active V12K-Ras4B. However, the amount of net charge, charge distribution and the length of the anchoring domain are important. Increasing the net charge and concentrating it close to the C-terminus increases not only the percentage of membrane bound protein, but also shifts the distribution from internal membranes, including the nuclear envelope, to the plasma membrane. While plasma membrane binding is necessary for V12K-Ras4B activity (MAPK activation and focus formation), we found that there are additional restrictions. In particular, mutants with very highly charged domains that bind almost exclusively to the plasma membrane show less transforming potential than expected. In addition, a construct with a short 'hypervariable' domain (7 amino acids) also has decreased transformation activity. These results suggest that specific interactions between K-Ras4B and the plasma membrane are required.

United States Army Rangers in Somalia: an analysis of combat casualties on an urban battlefield.

BACKGROUND: This study was undertaken to determined the differences in injury patterns between soldiers equipped with modern body armor in an urban environment compared with the soldiers of the Vietnam War. METHODS: From July 1998 to March 1999, data were collected for a retrospective analysis on all combat casualties sustained by United States military forces in Mogadishu, Somalia, on October 3 and 4, 1993. This was the largest and most recent urban battle involving United States ground forces since the Vietnam War. RESULTS: There were 125 combat casualties. Casualty distribution was similar to that of Vietnam; 11% died on the battlefield, 3% died after reaching a medical facility, 47% were evacuated, and 39% returned to duty. The incidence of bullet wounds in Somalia was higher than in Vietnam (55% vs. 30%), whereas there were fewer fragment injuries (31% vs. 48%). Blunt injury (12%) and burns (2%) caused the remaining injuries in Somalia. Fatal penetrating injuries in Somalia compared with Vietnam included wounds to the head and face (36% vs. 35%), neck (7% vs. 8%), thorax (14% vs. 39%), abdomen (14% vs. 7%), thoracoabdominal (7% vs. 2%), pelvis (14% vs. 2%), and extremities (7% vs. 7%). No missiles penetrated the solid armor plate protecting the combatants' anterior chests and upper abdomens. Most fatal penetrating injuries were caused by missiles entering through areas not protected by body armor, such as the face, neck, pelvis, and groin. Three patients with penetrating abdominal wounds died from exsanguination, and two of these three died after damage-control procedures. CONCLUSION: The incidence of fatal head wounds was similar to that in Vietnam in spite of modern Kevlar helmets. Body armor reduced the number of fatal penetrating chest injuries. Penetrating wounds to the unprotected face, groin, and pelvis caused significant mortality. These data may be used to design improved body armor.

PCTAIRE-1: characterization, subcellular distribution, and cell cycle-dependent kinase activity.

PCTAIRE-1 is a member of the cyclin-dependent kinase (cdk) family whose function is unknown. We examined the pattern of PCTAIRE-1 protein expression in a number of normal and transformed cell lines of various origins and found that the kinase is ubiquitous. Indirect immunofluorescence indicated that PCTAIRE-1 exhibits cytoplasmic distribution throughout the cell cycle. Confocal microscopy showed that PCTAIRE-1 does not colocalize with components of the cytoskeleton or with the endoplasmic reticulum. We found that endogenous PCTAIRE-1 and ectopically expressed PCTAIRE-1 display kinase activity when myelin basic protein is used as an acceptor substrate. Similar to other members of the cyclin-dependent kinase family, PCTAIRE-1 seems to require binding to a regulatory subunit to display kinase activity. PCTAIRE-1 activity is cell cycle dependent and displays a peak in the S and G2 phases. We show that the low level of kinase activity observed until the onset of S phase correlates with elevated tyrosine phosphorylation of the molecule.

Regulation of plasma membrane blebbing by the cytoskeleton.

When neuroblastoma cells are exposed to lysophosphatidic acid (LPA), they undergo a vigorous, but transient blebbing phase. The effect is sensitive to inhibition by staurosporine, KT 5926 (an inhibitor of myosin light chain kinase), and cytochalasin B, suggesting that LPA activates the phosphorylation of myosin light chain and increases the contractile activity of the actomyosin network. Cell contractions increase the intracellular pressure driving bleb formation. Calyculin, an inhibitor of protein phosphatase2A, also causes blebbing which continues as long as the drug is present, presumably by keeping myosin light chain in the phosphorylated state. Blebbing of neuroblastoma cells is regulated by the status of all three cytoskeletal systems: disassembly of microtubules by nocodazole and of intermediate filaments by acrylamide increased the number of blebbing cells. Cytochalasin B, on the other hand, prevents bleb retraction and, after prolonged incubation, bleb formation. These results are discussed in terms of a model viewing the cytoskeleton as an integrated network transmitting force throughout the cell. Bleb retraction was studied by transfecting neuroblastoma cells with a vector containing the gene for gamma-cytoplasmic actin fused to the green fluorescent protein EGFP (EGFP-actin). EGFP-actin was not detected on the membranes of extending blebs, but started accumulating along the cytoplasmic surface of blebs as soon as the extension phase came to an end and retraction set in. These results confirm earlier suggestions that actin polymerization is required for bleb retraction and for the first time directly relate the two events.

Recruitment of the LIM protein hic-5 to focal contacts of human platelets.

Platelets are anuclear, membrane-bounded fragments derived from megakaryocytes which, upon stimulation, assemble an actin skeleton including stress fibres and focal contacts. The focal contacts resemble those of tissue culture cells. However, they lack paxillin, a conspicuous component of these organelles. We found that instead of paxillin, platelets contain a related protein with a molecular mass of 55 kDa that crossreacts with a monoclonal antibody against paxillin. The gene for the 55 kDa protein was cloned from a bone marrow cDNA library and turned out to be identical to a recently discovered gene encoding hic-5. Like paxillin, hic-5 is a cytoskeletal protein containing four carboxy-terminal LIM domains and LD motifs in the amino-terminal half. The LIM domains of both hic-5 and paxillin are capable of targetting green fluorescent protein to focal contacts. In addition, GST-hic-5 precipitates the focal adhesion kinase pp125(FAK) and talin from platelet extracts. Only trace amounts of hic-5 occur in DAMI cells, a megakaryocytic cell line, and in megakaryocytes cultured from CD34+ cells obtained from umbilical cord blood. However, RT-polymerase chain reactions performed with RNA obtained from platelets gave a positive result when primers specific for hic-5 were used, but were negative with paxillin-specific primers, indicating that a switch from paxillin expression to hic-5 expression must occur late in the maturation of megakaryocytes into platelets.

Portable satellite telemedicine in practice.

The US army's first portable telemedicine unit was built in 1993 and comprised a 'ruggedized' videoconferencing unit. The unit was initially used in the United Nations' operations in Macedonia in February 1994 and subsequently in support of the Mobile Army Surgical Hospitals in Haiti, but its dimensions made it suitable only for locations where a move at short notice was unlikely. The second portable telemedicine unit comprised a PC linked to an Inmarsat B earth station through a modern. The unit allowed videoconferencing at 64 kbit/s. Three and a half years of clinical experience with both units has shown this to be quite adequate for the majority of clinical telemedicine. Portable telemedicine units have been a major benefit to medical commanders in the field.

Telemedicine in support of peacekeeping operations overseas: an audit.

BACKGROUND AND OBJECTIVE: Since 1993, the Department of Defense has augmented the medical support for Army units on peacekeeping operations in Macedonia through the medium of telemedicine. This project, known as Operation Primetime 1, was the first satellite-based telemedicine system deployed in support of remote primary-care physician in the U.S. military. Its declared aims are: (1) to improve the standard of care; (2) to reduce evacuations; (3) to support junior physicians in the field; and (4) to improve the military effectiveness of the deployed units. This paper audits the success in attaining those goals for the period January 1994 to April 1995. METHODS: A log was collated from the referring units and questionnaires completed by both referring and consulting physicians. The referring physicians were interviewed on their return from Macedonia, and a more detailed study was undertaken of cases in which a change in outcome was noted. Follow-up interview of consultants was not possible. RESULTS: A total of 53 consults were undertaken on 47 patients. The use of telemedicine affected the decision to evacuate 13 times (13/47), with a net reduction of 9 evacuations. Management of individual cases was changed in 30 of the 47 cases in which telemedicine was used. Physician confidence and military effectiveness were also improved. The level of utilization of the system was largely dependent on a training and sustainment program. Units and General Medical Officers who were trained in the clinical use of telemedicine and the technical sustainment of the equipment used the system; those who were not, did not. Most patients (45/47) were treated satisfactorily with a single consult. Telemedicine under these circumstances seems to be cost effective. The deployed sites chose the referral centers that provided the best service. CONCLUSIONS: Telemedicine is a valuable tool capable of augmenting medical support to deployed military units. A successful deployed telemedicine project requires an integrated support package that includes adequate provision for training and equipment sustainment at both ends of the link. Experience with telemedicine in Operation Primetime indicates the potential for substantial cost savings as well as cost-effective medical care. Further application of telemedicine should be encouraged. Successful deployment of telemedicine projects may hinge on an integrated support package.

Tactical combat casualty care in special operations.

U.S military medical personnel are currently trained to care for combat casualties using the principles taught in the Advanced Trauma Life Support (ATLS) course. The appropriateness of many of the measures taught in ATLS for the combat setting is unproven. A 2-year study to review this issue has been sponsored by the United States Special Operations Command. This paper presents the results of that study. We will review some of the factors that must be considered in caring for wounded patients on the battlefield with an emphasis on the Special Operations environment. A basic management protocol is proposed that organizes combat casualty care into three phases and suggests appropriate measures for each phase. A scenario-based approach is needed to plan in more detail for casualties on specific Special Operations missions, and several sample scenarios are presented and discussed.

Use of donkeys and their draught performance in smallholder farming in Zimbabwe.

Animal traction constitutes the most important source of power for agricultural work in smallholder farming in Zimbabwe. Two studies, a survey and a short term on-farm trial were conducted to evaluate the use of donkeys as draught animals. The survey covered 59 households in 2 smallholder farming areas. For the on-farm trial, 12 donkeys and 12 cattle were spanned separately in teams of 4 animals to plough 40 m x 70 m plots of medium textured soil. The survey findings highlighted the drought tolerance of donkeys compared to cattle. Mortality rates of donkeys were lower. Results of the draught performance trial indicated that donkeys ploughed less area per day (P < 0.05) and their walking speed was slower (P < 0.05) than cattle. There was no significant difference (P < 0.05) in draught force between the 2 species. The work rate per hour for ploughing with donkeys was 65% of that of cattle. It was concluded that donkeys play a critical role in providing draught power for smallholder farmers but that their potential is not fully utilised.

Refining prehospital physical assessment skills: a new teaching technique.

Physical assessment is a critically important skill in the prehospital setting, the performance of which is complicated by adverse environmental conditions. Emergency medical technicians (EMTs), paramedics, and others providing out-of-hospital emergency health care frequently receive training that does not adequately prepare them to perform an appropriate physical assessment. This is particularly true for such providers who support special operations as combat medics, wilderness EMTs, winter emergency care technicians, or EMT-tacticals. We describe a new training technique that emphasizes tactile sensory inputs rather than visual and auditory cues. The training strongly reinforces the importance of conducting a systematic survey.

Lysis of blood platelets by human osteosarcoma cells in vitro.

The in vitro interactions between human osteosarcoma (HOS) cells and platelets were studied in real time using video-enhanced microscopy. Interference reflection techniques showed that platelets were lysed within minutes after contacting HOS cells that had been treated with interferon-gamma. Untreated HOS cells lysed platelets less efficiently. Platelet lysis depended on platelet-tumor cell contact and on extracellular Ca2+. A number of possible mechanisms were excluded. Lysis of platelets in proximity to tumor cells can provide these with growth factors and thereby contribute to the metastasis-enhancing effect of platelets.

Pattern formation and handedness in the cytoskeleton of human platelets.

The cytoskeletal patterns of human platelets spread on a glass surface are analyzed. F-actin is arranged in patterns of parallel microfilaments, microfilaments forming triangles, or microfilaments radiating tangentially from a central ellipse or circle. Vinculin, a cytoskeletal protein, is located at both ends of the filaments. In platelets with tangentially radiating microfilaments, vinculin patches are aligned on the branches of a two-armed spiral. The spirals are always left-handed. Talin and two integrins (gpIIb-IIIa, vitronectin receptor), proteins usually associated with focal contacts in tissue culture cells, are not concentrated at the ends of microfilaments in human platelets. It is suggested that the distribution of vinculin is due to competitive aggregation of vinculin close to the inner leaflet of the ventral plasma membrane and that sites of cytoskeleton-membrane linkage are important for generating supramolecular asymmetries of biological systems.