Comparison of synthetic hydroxyapatite and porous polyethylene implants in eviscerated rabbit eyes

PURPOSE: Synthetic hydroxyapatite and porous polyethylene (Polipore) spheres were placed in rabbits' eviscerated cavities to evaluate tissue reaction and volume maintenance. METHODS: Fifty-six Norfolk albino rabbits underwent unilateral evisceration and implantation of synthetic hydroxyapatite (H group, 28 animals) or porous polyethylene spheres (P group, 28 animals). Postoperative reactions, animal behavior, and socket conditions were monitored. Light microscopy and morphometric evaluation with statistical analysis of the exenterated orbits were performed at 7, 15, 30, 60, 90, 120, and 180 days. Scanning electron microscopy was appraised 7, 60, and 180 days after surgery. RESULTS: Two animals from the H group and 1 from the P group had extrusion 7 days after surgery. Throughout the experimental period, the synthetic hydroxyapatite caused more inflammation than the porous polyethylene material. Ingrowth in the sphere occurred 7 to 15 days after the surgery in both groups, and the tissue reaction became denser at approximately 60 to 90 days, when bony metaplasia began in the H group. Volume maintenance was better in the P group and with a smaller pseudocapsule surrounding the implanted sphere than in the H group. CONCLUSIONS: Clinical findings demonstrated mild inflammation inside the sphere and in the pseudocapsule surrounding it and better cavity volume maintenance in the P group animals. The authors consider porous polyethylene a more suitable material than synthetic hydroxyapatite for use in anophthalmic cavity reconstruction.     

Unusual case of malignant pleomorphic fibrohistiocytoma of the abdominal wall

The authors report their experience with a case of a voluminous malignant pleomorphic histiocytoma of the anterior abdominal wall occurring in an 81-year-old female patient. She presented with a one-year history of a non-painful, poorly mobile tumefaction which had grown in size over the 2 months prior to admission. A preoperative CT scan confirmed the presence of a 10-cm mass located in the anterior abdominal wall. The patient underwent resection of the tumour and was discharged on postoperative day 15. A 12-month follow-up has so far revealed no evidence of recurrence. The authors go on to examine the diagnostic and therapeutic treatments of these rare neoplasms with reference to the international scientific literature. They confirm the validity of radiotherapy but stress the elective role of surgical treatment.     

Circadian organization of serum electrolytes in physiological aging

Age-related structural and neurochemical changes occurring in the central nervous system have been related to changes in some rhythmometric parameters. In spite of their clinical importance, only a few studies have investigated the modifications over time of serum electrolytes in senescence. The aim of our study was to evaluate the circadian pattern of serum potassium, chloride, sodium, calcium and phosphorus in 30 clinically healthy elderly subjects, with no cognitive impairment, and to compare the findings with those given by 24 healthy young controls. The subjects were synchronized as regards their daily activities, sleeping/waking habits, time/quality of meals and dietary electrolyte intake. After an overnight fast, samples were taken beginning at 08.00 and every 4 h thereafter until 20.00, and every 2 h from 20.00 to 04.00. Both the young and the elderly subjects exhibited statistically significant circadian rhythms for all serum electrolytes considered. Our findings suggest that circadian organization of serum electrolytes is maintained in physiological aging, even though it should be noted that sodium and phosphorus acrophases differed significantly in the two experimental groups.     

Impact of short-term preconceptional exposure to particulate air pollution on treatment outcome in couples undergoing in vitro fertilization and embryo transfer (IVF/ET)

Purpose  

To assess the potential effects of short-term exposure to particulate air pollution during follicular phase on clinical, laboratory, and pregnancy outcomes of women undergoing IVF/ET.     

An old workhorse of oxide investigations: new features of Co3O4

The electrochemical behaviour of Co₃O₄ from exhaustive cobalt nitrate decomposition (T=260–850°C) is investigated on graphite-supported electrodes, mainly relying on quasi-reversible results. Two well defined 1?e^? redox systems are observed related to Co²⁺/Co³⁺ and Co³⁺/Co⁴⁺ reactions of non-equivalent oxide surface sites. Oxide stoichiometry is directly estimated by voltammetry in ‘wet’ conditions and depends on preparation temperature as in ex situ solid state data. Adsorption of surface intermediates involved in charge transfer is examined. Langmuir and Temkin-type adsorption isotherms are obeyed for the Co²⁺/Co³⁺ and Co³⁺/Co⁴⁺ redox systems, respectively. Unusually negative (attractive) lateral interaction parameters are calculated for the latter system. Separation of oxide and graphite currents is achieved to permit real electrode surface area determination.     

Direct and indirect effects in vaccine efficacy and effectiveness

In 1915, Greenwood and Yule noted that for valid vaccine efficacy studies, exposure to infection in the vaccinated and the unvaccinated must be equal (Proc R Soc Med 1915;8(part 2):113-94). The direct effect of a vaccine, however, needs to be defined by the protection it confers given a specific amount of exposure to infection, not just a comparable exposure. In this paper, two classes of parameters are distinguished along lines differing from the conventional distinction between efficacy and effectiveness. Efficacy parameters attempt to control for exposure to infection and represent direct effects on individuals. Direct effectiveness parameters represent a mixture of direct effects on individuals and indirect effects in the population.     

Genetic structure of Plasmodium falciparum populations between lowland and highland sites and antimalarial drug resistance in Western Kenya

Human travel to malaria endemic lowlands from epidemic highlands has been shown to increase the risk of malaria infections in the highlands. In order to gain insight on the impact of human travel, we examined prevalence, genetic variability and population genetic structure of Plasmodium falciparum in asymptomatic children from one highland site and three surrounding malaria endemic lowland sites in Western Kenya, using multilocus microsatellite genotyping. We further analyzed the frequencies of mutations at the genes conferring resistance to chloroquine and sulfadoxine–pyrimethamine. We found a significant decrease in malaria prevalence in the highland site from 2006 to 2007, 1 year after the introduction of the artemisinin-based combination therapy as first-line treatment for uncomplicated malaria and the scale-up of insecticide-treated bed nets. Population genetic diversity, measured by the number of observed and effective microsatellite alleles and Nei's unbiased genetic diversity, was high and comparable for both highland and lowland populations. Analysis of molecular variance did not detect a significant genetic structure across highland and lowland regions. Similarly, mutations at key antimalarial-resistance codons of the pfcrt, pfmdr1, pfdhfr and pfdhps genes were found at comparable high frequencies in all four sites. High level of gene flow and lack of significant genetic structure in malaria parasites between highland and lowland areas suggest the importance of human travel in shaping parasite population structure.     

Non protein bound iron concentrations in amniotic fluid

OBJECTIVES: To investigate whether amniotic fluid concentrations of non protein bound iron (NPBI) vary with growth in healthy fetuses and also offer a reference curve in the second trimester of pregnancy. DESIGN AND METHODS: Amniotic fluid concentrations of NPBI were measured by HPLC in 118 women with physiological singleton pregnancies, who underwent amniocentesis for fetal karyotype between weeks 15 and 18 of gestation. RESULTS: NPBI increased progressively from weeks 14--15 to weeks 15--16, peaking at 17--18 weeks of gestation. NPBI values regressed positively with gestational age (GA). Multiple linear regression analysis between NPBI, as dependent variable, and various fetal parameters, as independent variables, showed a statistically significant regression coefficient with GA, bi-parietal diameter and transverse cerebellar diameter. CONCLUSIONS: The present data constitutes the first quantification of NPBI concentrations in amniotic fluid under physiological conditions. Correlations with GA and ultrasound fetal biometry suggest that NPBI may play a role in fetal growth.     

Possible Identification of Cervicogenic Headache Among Patients With Migraine: An Analysis of 374 Headaches

According to Sjaastad, the pain in cervicogenic headache, a form not recognized by the IHS, is long lasting and always side-locked unilateral. The frequency of side-locked unilateral pain (defined here as no change in side from onset) and other characteristics of cervicogenic headache were investigated in 300 outpatients using information collected on standard forms in structured interviews. Three hundred seventy-four headaches diagnosed according to IHS criteria were identified. Three hundred forty-eight of these headaches were long-lasting (duration of more than 4 hours); migraine (65%) followed by tension-type headache (25%) were the commonest forms. Side-locked unilaterality was present in 29% (101 of 348), and occurred most frequently in migrainous disorders not fulfilling the criteria (25 of 56, 44.6%). This group differed significantly from the other migraine conditions for longer pain duration ( P <0.02) and less frequent nausea, vomiting, photophobia, phonophobia ( P <0.0001), and aggravation by physical activity ( P <0.02). With these characteristics, this group resembled cervicogenic headache. However, in none of these patients was pain triggered by head or neck movements, and the frequency of head or neck trauma did not differ from other headaches. A more precise definition of clinical criteria for cervicogenic headache vs migraine is, therefore, required.