Ambulatory blood pressure monitoring is a useful clinical tool in nephrology

Hypertension is a key factor in the genesis and deterioration of many renal diseases and is also a risk factor for death in patients with end-stage renal disease. However, the standard methods of measurement are prone to variability, especially in patients undergoing dialysis. The technique of ambulatory blood pressure monitoring allows a better assessment of overall blood pressure levels and promises to assume a bigger role in the care of renal patients. Ambulatory blood pressure monitoring is widely used in hypertension trials, and the reports of several consensus meetings on the clinical uses of ambulatory blood pressure monitoring have been published. Two similar validation protocols now exist for ambulatory blood pressure monitors, and tables of population-based normal blood pressures for age and gender are available. The available evidence suggests that ambulatory blood pressure compared with blood pressure measured in the physician's office is better correlated to left ventricular mass in subjects with chronic renal disease. Furthermore, studies in subjects with chronic renal disease and those undergoing renal replacement therapy show that blood pressure control is suboptimal in many patients and that nocturnal blood pressure is generally higher than in control subjects. Further insights into overall blood pressure behavior in this population will certainly emerge in the future.     

MR pancreatography: a useful tool for evaluating pancreatic disorders

Magnetic resonance (MR) pancreatography is being used with increasing frequency as a noninvasive alternative to diagnostic endoscopic retrograde pancreatography in the evaluation of the pancreatic duct and various pathologic conditions of the pancreas. This recently developed technique allows improved spatial resolution and permits imaging of the entire pancreatico-biliary tract during a single breath hold. MR pancreatography can help identify the course and drainage pattern of the pancreatic duct and is useful in diagnosing congenital anomalies such as pancreas divisum and annular pancreas without the risk of inducing pancreatitis. In some instances, MR pancreatography may demonstrate duct disruption and associated fluid collections resulting from trauma. In recurrent acute pancreatitis, MR pancreatography is useful in suggesting the cause of the disease; in chronic pancreatitis, it is useful in depicting ductal anatomy, detecting strictures or intraductal calculi prior to surgery, and detecting complications such as pseudocysts and fistulas. In addition, MR pancreatography performed in conjunction with abdominal MR imaging is useful in identifying pancreatic malignancies as well as in establishing resectability and preventing unnecessary preoperative stent placement.     

Leukocytes of Biomphalaria glabrata: morphology and behavior of granulocytic cells in vitro

Resistance to 6-thioguanine was induced by 5-bromodeoxyuridine (BUdR) in synchronous Chinese hamster cells. The yield of mutant colonies was not proportional to the amount of BUdR incorporated into DNA; thus mutants were not due to mispairing of BUdR with guanine during replication. Few mutants were induced until BUdR concentrations exceeded that of the intracellular thymidine triphosphate pool and mutant yield was depressed by addition of thymidine to the medium. These data suggest that BUdR exerts an allosteric effect on the DNA synthesizing system which renders it more error prone.     

FluNet as a tool for global monitoring of influenza on the Web

In collaboration with the Institut National de la Santé et de la Recherche Médicale, the World Health Organization (WHO) has developed an Internet application linking the global WHO network of influenza centers (FluNet; http://oms.b3e.jussieu.fr/flunet/). During 1997, 22 pilot centers entered data on influenza activity and viral laboratory results directly into FluNet via secured access. In addition, 54 centers sent data to WHO for entry. Four countries (the Russian Federation, Romania, Sweden, and the United Kingdom) reported widespread outbreaks of at least 4 weeks' duration. The FluNet server ran 24 hours a day without interruption. To improve management and enhance standardization of reporting, this early-alert system for the global monitoring of influenza provides international and national authorities, the public, and the media with full access to real-time epidemiological and virological information.     

Invasion of the Nile Valley in Egypt by a hybrid of Biomphalaria glabrata and Biomphalaria alexandrina, snail vectors of Schistosoma mansoni

Two years (1996-1997) of systematic survey showed that a hybrid of Biomphalaria glabrata and Biomphalaria alexandrina has invaded the irrigation and drainage systems in the Nile Delta and the Valley nor the of El-Menya. However, the infestation of water courses by and the population density of this snail were variable in various localities. The infestation rate ranged between 7.1% in El-Fayoum Governorate and 52.6% in El-Dakahliya Governorate and the snail density from 2 snails/site to 69.7 snails/site in the same governorates, respectively. Comparing the survey results of the two study years in the sampling sites indicated that the hybrid snail has relatively increased in population density than B. alexandrina. The hybrid snail of B. glabrata and B. alexandrina was found alone in some sites, but was mostly associated with B. alexandrina. The results showed also that both Biomphalaria have almost the same major physicochemical requirements. However, the hybrid snails and B. alexandrina were found differently associated with aquatic snails and plants. The hybrid snail was found naturally infected with S. mansoni thus giving indication that it is presently participating in schistosomiasis mansoni transmission in Egypt.     

Rhodamine 123: a useful probe for monitoring T cell activation

The effect of nine factors on the outcome of classic in vitro screens testing the antagonistic action of endophytic bacterial isolates from grape vines against virulent Agrobacterium vitis has been examined. These factors were (i) the strain of A. vitis, (ii) the strain of endophyte, (iii) the growth medium of the pathogen, (iv) the growth medium of the endophyte, (v) the temperature of growth of the pathogen, (vi) the temperature of growth of the endophyte, (vii) the pH of growth of the pathogen, (viii) the pH of growth of the endophyte, and (ix) the medium of the assay plate. Analyses of variance of the full factorial design incorporating main effects and two- and three-way interactions accounted for 66% of the variance. All nine factors had a significant effect on the diameter of inhibition zones (p < 0.001). An examination of the three-way interactions revealed that generalizations were difficult to draw; each target agrobacterium had a specific response to a given antagonistic isolate. It was possible to determine that the growth history of bacterial strains, before they were administered to an assay plate to test for antagonism (especially the composition of the growth medium and the temperature of growth), had a profound effect on the outcome of the test. Generally the more chemically defined media produced less inhibition whereas the lower growth temperature of 15 degrees C produced more inhibition. These findings could be relevant to in situ inhibitory activity. The method used to conduct the inhibitory screen (order of strain application and the medium of the assay plate) had a profound influence on the results. These influences add to the caution necessary in the use of in vitro antagonistic screens for finding successful biocontrol agents.     

Schistosoma japonicum: in vitro cultivation of miracidium to daughter sporocyst using a Biomphalaria glabrata embryonic cell line

In vitro cultivation of Schistosoma japonicum miracidia to the mother sporocyst (MS) and then to the daughter sporocyst (DS) stage was achieved using the Biomphalaria glabrata embryonic (Bge) cell line as a coculture system. When comparing the effect of Bge cell and MS density on MS development, it was apparent that Bge cell density had a highly significant effect on both MS viability and growth. Viability and growth rate of MS cultured under high cell density conditions (350 cells/mm2) were almost 2 times greater than those of MS cultured under conditions of low cell density (60 cells/mm2). Growth under high cell density conditions corresponded to a 20 to 30 times increase in MS estimated volume within the first 9 weeks of cultivation. Emergence of fully formed motile DS was first observed after 11 weeks of cocultivation. A few DS lived for 14 weeks after emergence and attained a size of 770 +/- 100 microns in length and 48 +/- 13 microns in width. In contrast to what was observed in Bge cell/Schistosoma mansoni cocultures, Bge cells did not encapsulate S. japonicum MS. Our results show that, although the cellular interactions between Bge cells and schistosomes MS display some level of specificity, Bge cells apparently secrete soluble factors that permit excellent survival and can trigger advanced in vitro development of S. japonicum.     

Host choice by larval parasites: a study of Biomphalaria glabrata snails and Schistosoma mansoni miracidia related to host size

Within snail/trematode associations the age/size of the host at infection has consequences with regard to miracidial infection success, further intramolluscan parasite development and reproduction, and the host response, mainly in terms of growth and reproductive effort. Taking into account these differences, we were interested in determining whether miracidia could discriminate and make a choice between snails of different sizes. Using the Schistosoma mansoni/Biomphalaria glabrata system, we compared data on the snail infection rate and the mother sporocyst abundance among three size classes of snails (juvenile, subadult, and adult) exposed separately or together to the parasite larvae. When exposed individually, juvenile snails (3-5 mm) had significantly higher prevalence and abundance values than did subadult snails, followed by adult snails. In contrast, when snails of the three size classes were exposed together in heterogeneous size groups the prevalence and abundance values were always significantly higher for subadult snails of the 7- to 9-mm class than for juvenile and adult snails. A host choice experiment confirmed that significantly more miracidia were attracted by subadult snails, suggesting that the parasite has been selected for specific locating and recognition mechanisms increasing the infection rate of subadult snails when the latter have been exposed in a heterogeneous size group. Selective forces that may be responsible for such a preferential infectivity of the parasite vis-à-vis particular host age/size class are discussed in relation to host resources and host responses.     

The psychological autopsy: a useful tool for determining proximate causation in suicide cases

This overview article examines the applications of the psychological autopsy method in determining proximate causation in suicide cases. The article reviews the history of the psychological autopsy and describes its procedure and how it has proved helpful in explicating proximate causation. The five standards currently used by the courts to determine proximate causation in suicide cases are described, as are a variety of applications of the psychological autopsy method, including its application to workers' compensation cases, product liability cases, and medical malpractice cases. In particular, issues of prediction and protection are addressed. Finally, there is a discussion of an application of the psychological autopsy to criminal cases. The article concludes with a discussion of the issues raised in the use of the psychological autopsy during expert testimony and the considerations that should be addressed by an expert witness contemplating the use of the psychological autopsy method.     

Olfactory epithelial organotypic slice cultures: a useful tool for investigating olfactory neural development

An in vitro slice culture was established for investigating olfactory neural development. The olfactory epithelium was dissected from embryonic day 13 rats; 400 microns slices were cultured for 5 days in serum-free medium on Millicell-CM membranes coated with different substrates. The slices were grown in the absence of their appropriate target, the olfactory bulb, or CNS derived glia. The cultures mimic many features of in vivo development. Cells in the olfactory epithelium slices differentiate into neurons that express olfactory marker protein (OMP). OMP-positive cells have the characteristic morphology of olfactory receptor neurons: a short dendrite and a single thin axon. The slices support robust axon outgrowth. In single-label experiments, many axons expressed neural specific tubulin, growth-associated protein 43 and OMP. Axons appeared to grow equally well on membranes coated with type I rat tail collagen, laminin or fibronectin. The cultures exhibit organotypic polarity with an apical side rich in olfactory neurons and a basal side supporting axon outgrowth. Numerous cells migrate out of the slices, of which a small minority was identified as neurons based on the expression of neural specific tubulin and HuD, a nuclear antigen, expressed exclusively in differentiated neurons. Most of the migrating cells, however, were positive for glial fibrillary acidic protein and S-100, indicating that they are differentiated glia. A subpopulation of these glial cells also expressed low-affinity nerve growth factor receptors, indicating that they are olfactory Schwann cells. Both migrating neurons and glia were frequently associated with axons growing out of the slice. In some cases, axons extended in advance of migrating cells. This suggests that olfactory receptor neurons in organotypic cultures require neither a pre-established glial/neuronal cellular terrain nor any target tissue for successful axon outgrowth. Organotypic olfactory epithelial slice cultures may be useful for investigating cellular and molecular mechanisms that regulate early olfactory development and function.     

Magnetic resonance imaging: a useful tool for evaluation of bone prior to implant surgery

OBJECTIVE: To illustrate the potential for use of magnetic resonance imaging (MRI) to gain full sectional information before placement of osseo-integrated dental implants, with no patient exposure to ionising radiation. MATERIALS AND METHODS: Four typical cases are illustrated, the patients being imaged in a one tesla MRI scanner. The setting up of the sequences is explained, along with the use of an imaging/surgical template with gadolinium markers. RESULTS: MRI clearly shows full sectional detail of available bone for safe implant placement, and allows the delineation of cortical and cancellous bone to attain maximum implant length and stability. Vital structures and the floor of the maxillary sinus are clearly shown. CONCLUSIONS: MRI allows the surgeon to assess cases for suitability to place dental implants with confidence. The ability to scan directly at any desired plane, with no reformatting, and to relate this information to a surgical template gives predictable surgery. MRI is a sectional imaging modality giving information about the 3-dimensional relationship of the vital structures, without using ionising radiation. It therefore deserves consideration as an alternative to computed tomography. However, further work is indicated to investigate the relative technical merits of the two imaging modalities.     

Detection of lead in environmental objects and biologic materials during monitoring]

The authors specified methods to detect lead in biologic materials. The quality control covered use of Russian and foreign standard samples, the results proved to agree. Lead was detected by AAS technique (direct and flow-type variants with preliminary concentration of lead) and ELRA method. The authors determined measurement limits sufficient for analysis of complex biologic materials. The measurement range for lead varied from 0.002 mg/kg (plants) to 3,000 mg/kg (soil); the range of serum lead levels was < 0.5-39 mg/dl.     

SvO2 monitoring: tool for evaluating patient outcomes

Current technology provides a simple and reliable method for continuous monitoring of mixed venous oxygen saturation (SvO2). Assessment of this value represents an important vital sign for oxygen supply and demand balance for the critical care patient. Nurses can use SvO2 monitoring to assess outcomes of therapy.     

Lichens as a tool for biogeochemical prospecting

The heavy metal content in lichens and vascular plants from abandoned copper mining areas, Gerakario (Kilkis) and Megali Panagia (Chalkidiki), have been compared with metal content in soil in order to assess their efficiency to accumulate five metals (Cu, Mn, Pb, Zn, and Cr). The average metal content in the mineralized soil of Gerakario was, in descending order, Cu, Mn, Pb, Zn, and Cr, and in Chalkidiki it was Cu, Mn, Cr, Pb, and Zn. The epilithic lichens (Neophuscelia pulla) accumulated the highest amount of Cu and Pb, and Xanthoparmelia taractica accumulated the highest amount of Zn. All the lichens revealed significant (P < 0.05) correlation between Cu content in soil and that in thalli. Out of five metals studied, four (Cu, Pb, Mn, and Cr) in the epigeic lichen Cladonia convoluta, two (Cu and Mn) in both epilithic lichen N. pulla and X. taractica, and one (Pb) in vascular plant Minuartia (root) were significantly (P < 0.05) correlated between their metal content in plant tissue and in soil. Further, discoloration of C. convoluta with higher Cu concentrations adds a visible clue for biogeochemical exploration. Thus, lichens along with other symptomatic species will help in locating mining areas.     

Protein engineering as a tool for crystallography

A questionnaire survey of 260 health care workers from 13 randomly selected health care facilities was undertaken. Their knowledge, attitude, belief and blood handling practices regarding HIV/AIDS were enquired about. Virtually all (99.0%) respondents had heard about AIDS but only 57.0% had seen an AIDS patient before. Although 83.0% knew that AIDS is caused by a virus, a high proportion still confuses mode of transmission with causative agent. Deficient knowledge was exhibited when asked about groups of people who were at a higher risk of contracting HIV and AIDS: Only 54.6% and 51.5% identified homosexuals and i.v. drug users as being at a higher risk. Almost all (97.0%) of our respondents claimed to have been more careful in their blood handling practices since the emergence of AIDS, 68.5% wore gloves for all procedures involving handling of blood and 28.5% sometimes although as many as 30.4%, 40.4% and 18.1% do not wear gloves for cleaning up blood stained materials, nursing procedures and taking obstetric delivery respectively. It was evident from their responses that not all the health workers knew the correct method for disposing of used bloodstained instruments and left-over blood samples and neither were they all adhering to the safety guidelines recommended for handling these materials. Education of all health care workers in Nigeria on the Universal Precautions Guidelines issued by the Centers for Disease Control (CDC) in 1987 regarding blood, body fluids and contaminated instruments' handling precautions is urgently recommended.     

The reflective process as a tool for learning: a personal account

In 34 inpatients, 22 with diagnosis of rheumatoid arthritis according to revised ACR criteria and 12 with diagnosis of other diseases without affection of the hands served like control group we measured grip strength in 4 time period during the day (7, 11, 15, 19 hours) with the Martin's vigorimeter. Mean grip strength value was statistically lower in patients with rheumatoid arthritis in all four time periods (P < 0.005). There is general trend of the rising grip strength since morning to evening without statistically relevance. Grip strength firmly linear negatively correlated with the grade of morning stiffness.     

PCBs as environmental estrogens: turtle sex determination as a biomarker of environmental contamination

Polychlorinated biphenyls (PCBs) are widespread, low-level environmental pollutants associated with adverse health effects such as immune suppression and teratogenicity. There is increasing evidence that some PCB compounds are capable of disrupting reproductive and endocrine function in fish, birds, and mammals, including humans, particularly during development. Research on the mechanism through which these compounds act to alter reproductive function indicates estrogenic activity, whereby the compounds may be altering sexual differentiation. Here we demonstrate the estrogenic effect of some PCBs by reversing gonadal sex in a reptile species that exhibits temperature-dependent sex determination.