14 research outputs found
Treatment of Supracondylar Humerus Fractures in Children: Minimal Possible Duration of Immobilization
In the period from January 1980 until December 1990 we treated 147 children and
adolescents with supracondylar humerus fracture, and followed the outcome in 127 of
them. Three (2.4%) patients had no displacement of fractured bones and were treated
only with plaster cast immobilization. Twenty three (18.1%) underwent closed reduction
of fragments and application of a plaster cast. The majority (97; 76.4%) required manual
reduction and the fixation of segments with Kirschner\u27s wires laterally and medially.
Four (3.1%) patients were treated with open reduction and fixation with
Kirschner\u27s wires. Both plaster cast immobilization and fragment fixation with
Kirschner\u27s wires lasted only 14 days and were immediately followed by rehabilitation.
Such a short immobilization of extremities or fixation of fragments did not result in any
complication. Of 56 children available for long-term follow-up, we achieved excellent
treatment results in 43 (76.6%) of the patients, good and fair in 12 (21.5%), and a poor
result in only 1 patient (1.8%). There were no permanent vascular or neurological complications
apart from slight weakness of the ulnar nerve in 3 patients. In conclusion 14
days seemed to be the biological minimum of time needed for this type of fracture to heal
in children and adolescents. Fixation of the fragments with Kirschner\u27s wires and immobilization
of the extremity for only 14 days brings a significant reduction of total
treatment expenses, avoids repeated x-ray examination, facilitates early physical therapy
and returns the child to its family
Graphene-based waveguide resonators for submillimeter-wave applications
Utilization of graphene covered waveguide inserts to form tunable waveguide resonators is theoretically explained and rigorously investigated by means of full-wave numerical electromagnetic simulations. Instead of using graphene-based switching elements, the concept we propose incorporates graphene sheets as parts of a resonator. Electrostatic tuning of the graphene surface conductivity leads to changes in the electromagnetic field boundary conditions at the resonator edges and surfaces, thus producing an effect similar to varying the electrical length of a resonator. The presented outline of the theoretical background serves to give phenomenological insight into the resonator behavior, but it can also be used to develop customized software tools for design and optimization of graphene-based resonators and filters. Due to the linear dependence of the imaginary part of the graphene surface impedance on frequency, the proposed concept was expected to become effective for frequencies above 100 GHz, which is confirmed by the numerical simulations. A frequency range from 100 GHz up to 1100 GHz, where the rectangular waveguides are used, is considered. Simple, all-graphene-based resonators are analyzed first, to assess the achievable tunability and to check the performance throughout the considered frequency range. Grapheneāmetal combined waveguide resonators are proposed in order to preserve the excellent quality factors typical for the type of waveguide discontinuities used. Dependence of resonator properties on key design parameters is studied in detail. Dependence of resonator properties throughout the frequency range of interest is studied using eight different waveguide sections appropriate for different frequency intervals. Proposed resonators are aimed at applications in the submillimeter-wave spectral region, serving as the compact tunable components for the design of bandpass filters and other devices
Normal and Cut-Off Values of the Cytokinesis-Block Micronucleus Assay on Peripheral Blood Lymphocytes in the Croatian General Population
Mikronukleus (MN) test na limfocitima periferne krvi jedna je od najvažnijih metoda koje se primjenjuju u citogenetiÄkom nadzoru. Osnovni preduvjet za primjenu nekog testa u svrhu nadzora profesionalno izloženih populacija jest poznavanje normalnih vrijednosti promatranoga bioloÅ”kog pokazatelja (biomarkera) u
kontrolnoj populaciji. Baze podataka na razini opÄe populacije moraju se redovito obnavljati novim podacima. Cilj ovog istraživanja bio je utvrditi normalne i graniÄne vrijednosti MN-testa na limfocitima
periferne krvi 200 zdravih ispitanika obaju spolova iz opÄe populacije Republike Hrvatske te ispitati koji Äimbenici pridonose spontanom nastanku MN. Na razini istražene populacije utvrÄeno je prosjeÄno
(6,90Ā±3,32) MN (medijan 7 MN), dok je raspon pojedinaÄnih vrijednosti iznosio 0 do 18 MN u 1000 binuklearnih stanica. Gornja graniÄna vrijednost dobivena izraÄunavanjem 95. percentila za cjelokupnu promatranu populaciju iznosi 12,5 MN na 1000 limfocita. UtvrÄeno je da na spontani nastanak MN utjeÄu spol, dob i navika puÅ”enja. Žene u prosjeku imaju viÅ”e vrijednosti svih parametara MN-testa od muÅ”karaca, a u njih je bio i naglaÅ”eniji porast vrijednosti citogenetiÄkog nalaza zbog navike puÅ”enja.
Kako su literaturni podaci o utjecaju puÅ”enja cigareta na nastanak MN kontradiktorni, planiran je nastavak istraživanja radi razjaÅ”njavanja utjecaja dnevno utroÅ”enog broja cigareta i ukupnog trajanja puÅ”aÄkog staža na vrijednosti parametara MN-testa. Usporedba rezultata s literaturnim podacima potvrdila je da su
dobivene vrijednosti u skladu s vrijednostima MN-testa zabilježenim na opÄoj populaciji u drugim svjetskim laboratorijima. Normalne i graniÄne vrijednosti MN-testa utvrÄene u ovome istraživanju poslužit Äe kao osnova za usporedbu i tumaÄenje nalaza MN-testa u ispitanika izloženih populacija te daljnju nadogradnju laboratorijske baze podataka.The cytokinesis-block micronucleus (CBMN) assay on peripheral blood lymphocytes is one of the most important methods employed in cytogenetic biomonitoring. For the purposes of biological dosimetry, it is important to kno the spontaneous frequency of a biomarker and its normal values in general population.
These values are used for population databases, which should be updated regularly. In this study, MN levels were investigated in cytokinesis-blocked lymphocytes of 200 healthy male and female blood donors selected at random from the general population of Croatia. The aim was to assess the variability and determine possible infl uences of external and/or internal factors on the background levels of MN and to establish the cut-off value for the CBMN assay. The background frequency of MN was (6.90Ā±3.32) MN (median 7 MN) and the range was 0 to 18 MN per 1000 binuclear lymphocytes. The cut-off value, which corresponds to 95th percentile of the distribution of 200 individual values, was 12.5 MN. Spontaneous formation of MN was infl uenced by sex, age, and smoking. Women had higher MN levels than men.
However, only age and smoking signifi cantly increased the values of all parameters evaluated by the CBMN assay. Since the existing literature data on smoking-related formation of MN are contradictory,
we will continue these investigations to resolve how the number of cigarettes smoked per day and the duration of smoking in years infl uence the results of the CBMN assay. Our results are consistent with the background MN frequencies reported by other cytogenetic laboratories worldwide. Normal and cut-off values estimated in this study will be used to update the current general population data and as reference for occupationally or accidental exposure
Are the platelet indices useful biomarkers of arteriovenous fistula thrombosis in hemodialysis patients?
P.718 Procognitive effect of a single dose of magnesium in novel object recognition test, in healthy and corticosterone treated rats
The frequency of premature segregation of centromeres in persons exposed to ionizing radiation
U ovom radu istraživana je uÄestalost prevremene centromerne deobe (PCD) u metafazama medicinskog osoblja profesionalno izloženog jonizujuÄem zraÄenju koji su imali pozitivan nalaz hromozomskih aberacija, u odnosu na kontrolnu grupu koja nije profesionalno izložena efektima pomenutog zraÄenja. Evaluacija klastogenog efekta izvedena je pomoÄu Moorchaedove mikrometode te aplikacijom tehnika fluorescentne in situ hibridizacije (FISH). Analizom rezultata zapaženo je da postoji statistiÄki znaÄajna razlika (p lt 0.05) u frekvenciji metafaza PCD na bilo kom od observiranih hromozoma kao i na ukupnom broju hromozoma sa PCD izmeÄu dve grupe ispitanika (profesionalno izloženi i kontrole). Fluorescentnom in situ hibridizacijom (FISH) praÄenje centromerni region hromozoma 18 na metafazama i interfaznim jedrima, Å”to je pokazala da je pojavljivanje PCD na hromozomu 18 bilo 11,19% na metafazama i 10.88% na interfaznim jedrima, dok je kod kontrolne grupe ispitanika pojavljivanje PCD na hromozomu 18 bilo 7,58%, na metafazama, i 7.78% na interfaznim jedrima. Dakle, ovim istraživanjemj e utvrÄeno da kod ispitanika profesionalno izloženih jonizujuÄem zraÄenju, postoji fenomen PCD verifikovan u metafazama i interfaznim jedrima, u znaÄajno frekventnijem obimu nego Å”to je to sluÄaj sa kontrolnom grupom ispitanika. Indukcija PCD raznim genotoksiÄnim agensima upuÄuje da se PCD sagleda kao parametar genotoksiÄnog rizika po Äoveka i njegovu životu sredinu.The objective of study was to establish the incidence of PCD in metaphases of medical personnel occupationally exposed to ionizing radiation in relation to the controls. Moorchaed's micromethod and fluorescent in situ hybridization (FISH) were used for evaluation of clastogenic effect. The analysis of results revealed statistically significant difference (p lt 0.05) of PCD manifestation in metaphases any chromosome and the control group. In addition, significantly higher values were found in a total number of chromosomes with PCD than in the controls (p lt 0.05). Fluorescent in situ hybridization (FISH) was used to monitor the centromeric region of chromosome 18 in metaphases and interphasic nuclei. Cytogenic analysis showed that the manifestation of PCD in chromosome 18 was 11.19% in metaphases and 10.88% in interphasic nuclei, while in the controls, the presentation of PCD in chromosome 18 was 7.58% in mataphases and 7.78% in interphasic nuclei. The study confirmed that the subjects occupationally exposed to ionizing radiation had PCD phenomenon, wich was verified in metaphases and interphasic nuclei in a significant frequency rate. The induction of PCD by various genotoxic agents directs us to recognize PCD as parametar of genotoxic risk to mankind and its environment