A Novel Approach to Major Surgery: Tracking Its Pathophysiologic Footprints.

BACKGROUND: To study the 'metabolic profile' of different surgical procedures and correlate it with pertinent surgical details and postoperative complications. METHODS: We conducted a prospective pilot study of 70 patients, ten for each of the seven following groups: (1) laparoscopic cholecystectomy, (2) incisional hernia repair, (3) laparoscopic and (4) open colon surgery, (5) upper gastrointestinal, (6) hepatic, and (7) pancreatic resections. Biochemical assessment included white blood cell count (WBC), C-reactive protein (CRP), glucose, triglycerides (TG), albumin (Alb), and pre-albumin (Pre-Alb), from the day before surgery until 5 days thereafter. Biological markers were compared for major versus minor surgery groups, which were defined on a clinical basis. Univariable analysis was used to identify risk factors for postoperative complications and p < 0.05 was the significance threshold. RESULTS: Common findings in all surgery groups were the acute inflammatory response (↑: WBC, CRP, ↓: TG, Alb, pre-Alb). Using cut-off values of 240 min operative (OR) time and 300 ml estimated blood loss (EBL), laparoscopic cholecystectomy, incisional hernia repair, and laparoscopic colectomy could be distinguished from open colectomy, upper gastrointestinal, liver, and pancreas resections. In a biochemical level, increased CRP and reduced postoperative Alb levels were highly discriminative of all types of 'major surgery.' Significant risk factors for postoperative complications were age, male gender, malignancy, longer OR time, higher blood loss, high CRP, and low Alb levels. CONCLUSIONS: Biochemically, CRP and Alb levels can help quantify the magnitude of the surgical trauma, which is correlated with adverse outcomes.

Polymeerien erotus ultrasuodatuksella

Työssä selvitettiin suodatusolosuhteiden vaikutusta neutraalien polymeerien pidättymiseen niiden vesiliuoksia suodatettaessa. Suodatuksissa käytettiin kahta regeneroidusta selluloosasta valmistettua ultrasuodatuskalvoa (Microdyn-Nadir UC 030T ja JSC STC Vladipor C 30V). Malliaineina käytettiin polyetyleeniglykolia ja dekstraania. Kirjallisuusosassa esiteltiin aluksi lyhyesti ultrasuodatus erotusmenetelmänä. Lisäksi käsiteltiin ultrasuodatuskalvojen huokoskoon karakterisointimenetelmiä ja selvitettiin polymeerien erottumiseen ultrasuodatuksen aikana vaikuttavia tekijöitä. Työn kokeellisessa osassa tutkittiin paineen ja virtausnopeuden vaikutusta malliaineiden pidättymiseen ultrasuodatuskalvoilla. Lisäksi pyrittiin löytämään suodatusolosuhteet, joissa toinen aineista läpäisisi suodatuskalvon lähes täydellisesti toisen konsentroituessa syöttöliuokseen. Työssä myös määritettiin tutkimuksissa käytetyille kalvoille katkaisukoko, joka kuvaa kalvon kykyä pidättää moolimassaltaan erikokoisia molekyylejä. Lisäksi kokeellisessa osassa selvitettiin työssä käytettyjen kalvojen tasalaatuisuutta vertailemalla keskenään samanlaisissa suodatusolosuhteissa eri kalvopaloilla tehtyjen suodatusten tuloksia. Työssä saatiin erotettua kaksi lähes samankokoista malliaineeksi valittua neutraalia polymeeriä toisistaan siten, että toinen aine pidättyi kalvolla huomattavasti toista ainetta paremmin. Parhaimpaan erotustulokseen päästiin, kun permeaattivuo kalvon läpi oli noin 400 l/(m2 h). Tällöin suodatuspaine oli noin 2 bar ja virtausnopeus alle 2 m/s. Työn aikana määritettyjen katkaisukokojen havaittiin poikkeavan huomattavasti kalvojen valmistajien ilmoittamista arvoista, mutta olevan kuitenkin samaa suuruusluokkaa kuin muiden tutkimusryhmien vastaaville ultrasuodatuskalvoille esittämät arvot. Työn tulosten perusteella C 30V olisi hieman tasalaatuisempi kalvo kuin UC 030T.

The role of ultrasonography in the measurement of subcutaneous and visceral fat and its correlation with hepatic steatosis

Objective To evaluate the sonographic measurement of subcutaneous and visceral fat in correlation with the grade of hepatic steatosis. Materials and Methods In the period from October 2012 to January 2013, 365 patients were evaluated. The subcutaneous and visceral fat thicknesses were measured with a convex, 3–4 MHz transducer transversely placed 1 cm above the umbilical scar. The distance between the internal aspect of the abdominal rectus muscle and the posterior aortic wall in the abdominal midline was considered for measurement of the visceral fat. Increased liver echogenicity, blurring of vascular margins and increased acoustic attenuation were the parameters considered in the quantification of hepatic steatosis. Results Steatosis was found in 38% of the study sample. In the detection of moderate to severe steatosis, the area under the ROC curve was 0.96 for women and 0.99 for men, indicating cut-off values for visceral fat thickness of 9 cm and 10 cm, respectively. Conclusion The present study evidenced the correlation between steatosis and visceral fat thickness and suggested values for visceral fat thickness to allow the differentiation of normality from risk for steatohepatitis.

Food Safety Testing: Rapid Molecular Methods for Chemical and Biological Hazards

The central goal of food safety policy in the European Union (EU) is to protect consumer health by guaranteeing a high level of food safety throughout the food chain. This goal can in part be achieved by testing foodstuffs for the presence of various chemical and biological hazards. The aim of this study was to facilitate food safety testing by providing rapid and user-friendly methods for the detection of particular food-related hazards. Heterogeneous competitive time-resolved fluoroimmunoassays were developed for the detection of selected veterinary residues, that is coccidiostat residues, in eggs and chicken liver. After a simplified sample preparation procedure, the immunoassays were performed either in manual format with dissociation-enhanced measurement or in automated format with pre-dried assay reagents and surface measurement. Although the assays were primarily designed for screening purposes providing only qualitative results, they could also be used in a quantitative mode. All the developed assays had good performance characteristics enabling reliable screening of samples at concentration levels required by the authorities. A novel polymerase chain reaction (PCR)-based assay system was developed for the detection of Salmonella spp. in food. The sample preparation included a short non-selective pre-enrichment step, after which the target cells were collected with immunomagnetic beads and applied to PCR reaction vessels containing all the reagents required for the assay in dry form. The homogeneous PCR assay was performed with a novel instrument platform, GenomEra^™, and the qualitative assay results were automatically interpreted based on end-point time-resolved fluorescence measurements and cut-off values. The assay was validated using various food matrices spiked with sub-lethally injured Salmonella cells at levels of 1-10 colony forming units (CFU)/25 g of food. The main advantage of the system was the exceptionally short time to result; the entire process starting from the pre-enrichment and ending with the PCR result could be completed in eight hours. In conclusion, molecular methods using state-of-the-art assay techniques were developed for food safety testing. The combination of time-resolved fluorescence detection and ready-to-use reagents enabled sensitive assays easily amenable to automation. Consequently, together with the simplified sample preparation, these methods could prove to be applicable in routine testing.

Reaaliaikaisen esikäsittelyn kehittäminen hemiselluloosa-analytiikalle

Tämän työn tavoitteena oli kehittää esikäsittelymenetelmä, jolla voidaan reaaliaikaisesti vähentää hydrolysaatin ligniinipitoisuutta ja näin vähentää fluoresenssia hemiselluloosan analysoimisessa. Työn kirjallisuusosassa käsitellään hemiselluloosien rakennetta sekä niiden erottamista puusta, sekä käydään läpi hemiselluloosien käyttömahdollisuuksia ja niiden reaaliaikaiseen analysointiin soveltuvia tekniikoita. Kokeellisessa osassa tutkittiin ultrasuodatusta sekä adsorptiohartsikäsittelyä hydrolysaatin esikäsittelynä ennen Raman-analyysiä. Esikäsittelyn tavoitteena oli vähentää Raman-analyysia häiritsevää ligniinistä johtuvaa fluoresenssia. Suodatukset tehtiin Amicon-suodatuslaitteistolla käyttäen viittä eri suodatuskalvoa. Hartsikäsittelyissä käytettiin Amberliten XAD16 ja XAD7HP adsorbtiohartseja. Hartsisuhteina käytettiin 1/80, 1/40, 1/19 ja 1/13. Käytetyt ultrauodatuskalvot osoittautuivat suodatusnäytteistä tehtyjen HPLC-analyysien perusteella cut-off-luvultaan liian pieniksi, sillä hemiselluloosien ja ligniinin erotus ei onnistunut, vaan molemmat väkevöityivät konsentraattiin. Hartsikäsittelyillä saatiin ligniiniä poistettua aiheuttamatta hemiselluloosahäviöitä. Parhaimmillaan ligniinin poistumista kuvaava UV-absorbanssi pieneni hartsilla XAD16 37 % ja hartsilla XAD7 25 %. Vaikka ligniinipitoisuus aleni, näytteet fluoresoivat edelleen voimakkaasti Raman-mittauksessa. Tulosten perusteella näyttäisi siltä, että hartsikäsittelyä optimoimalla analyysiä häiritsevää fluoresenssia olisi edelleen mahdollista vähentää.

Application of morphometry, static DNA ploidy analysis, and steroid receptor expression in diagnosis and prognosis of Libyan breast cancer

The aim of this study was to describe the demographic, clinicopathological, biological and morphometric features of Libyan breast cancer patients. The supporting value of nuclear morphometry and static image cytometry in the sensitivity for detecting breast cancer in conventional fine-needle aspiration biopsies were estimated. The findings were compared with findings in breast cancer in Finland and Nigeria. In addation, the value of ER and PR were evaluated. There were 131 histological samples, 41 cytological samples, and demographic and clinicopathological data from 234 Libyan patients. The Libyan breast cancer is dominantly premenopausal and in this feature it is similar to breast cancer in sub-Saharan Africans, but clearly different from breast cancer in Europeans, whose cancers are dominantly postmenopausal in character. At presention most Libyan patients have locally advanced disease, which is associated with poor survival rates. Nuclear morphometry and image DNA cytometry agree with earlier published data in the Finnish population and indicate that nuclear size and DNA analysis of nuclear content can be used to increase the cytological sensitivity and specificity in doubtful breast lesions, particularly when free cell sampling method is used. Combination of the morphometric data with earlier free cell data gave the following diagnostic guidelines: Range of overlap in free cell samples: 55 μm2 -71 μm2. Cut-off values for diagnostic purposes: Mean nuclear area (MNA) >54 μm2 for 100% detection of malignant cases (specificity 84 %), MNA < 72 μm2 for 100% detection of benign cases (sensitivity 91%). Histomorphometry showed a significant correlation between the MNA and most clinicopathological features, with the strongest association observed for histological grade (p <0.0001). MNA seems to be a prognosticator in Libyan breast cancer (Pearson’s test r = - 0.29, p = 0.019), but at lower level of significance than in the European material. A corresponding relationship was not found in shape-related morphometric features. ER and PR staining scores were in correlation with the clinical stage (p= 0.017, and 0.015, respectively), and also associated with lymph node negative patients (p=0.03, p=0.05, respectively). Receptor-positive (HR+) patients had a better survival. The fraction of HR+ cases among Libyan breast cancers is about the same as the fraction of positive cases in European breast cancer. The study suggests that also weak staining (corresponding to as few as 1% positive cells) has prognostic value. The prognostic significance may be associated with the practice to use antihormonal therapy in HR+ cases. The low survival and advanced presentation is associated with active cell proliferation, atypical nuclear morphology and aneuploid nuclear DNA content in Libyan breast cancer patients. The findings support the idea that breast cancer is not one type of disease, but should probably be classified into premenopausal and post menopausal types.

Sellutehtaan prosessien jätevesien puhdistaminen membraanitekniikalla

Tässä työssä tarkoituksena on tutkia mahdollisuuksia sellutehtaan eri jätevesien puhdistukseen uudelleenkäyttöä varten. Yleensä tutkimuksen kohteena ovat yleensä valkaisun alkalisen suodokset, koska niiden suodattaminen on ollut helppoa membraanitekniikalla. Tässä tutkimuksessa kuitenkin kiinnostuksen kohteena ovat valkaisun happamat suodokset ja kuorimon jätevedet. Tutkimuksessa käytettiin viittä membraania, joista kolme on ultrasuodatusmembraaneja ja kaksi nanosuodatusmembraaneja. Näiden katkaisukoot ovat väillä 30 000 -200 Da. Konsentraatiosuodatukset suoritettiin CR 250 -suodattimella. Syötöstä, konsentraatista ja permeaatista otettujen näytteiden analyysien pohjalta laskettujen retentioiden perusteella nanosuodatusmembraani NF270 antoi parhaan tuloksen. Tällä membraanilla kuorimon jätevesien suodatuksessa retentioksi saatiin kaikilla osa-alueilla vähintään 80 %, mutta valkaisun happamien suodosten tulokset olivat alhaisempia. Suodatusten perusteella voitiin laskea tarvittava kapasiteetti ja suodatuspinta-ala suodatus yksiköille. Kummassakin tapauksessa suodatuksen syöttömäärät määräytyivät erään suomalaisen sellutehtaan valkaisussa ja kuorimolla syntyvien jätevesimäärien mukaan. Suodatusyksiköiden kooksi saatiin valkaisun happamien suodosten suodattamiseen 54 CR 1010 -suodatinta ja kuorimon jätevesien suodattamiseen 4 CR 1010-suodatinta.

Measurement of Ki-67 antigen in 159 pituitary adenomas using the MIB-1 monoclonal antibody

Pituitary adenomas sometimes show rapid growth and recurrence, and about one third invade the structures surrounding the sella turcica. In an attempt to determine aggressive behavior at an early stage, we used the MIB-1 antibody to identify the Ki-67 antigen. The present study was designed to evaluate pituitary adenomatous tissue in terms of secretion and proliferation and to correlate the Ki-67 index with hormone phenotype and invasive behavior. Material from 159 patients submitted to one or more resections of pituitary adenomas was evaluated. Forty-two non-secretory adenomas and 43 adenomas immunoreactive for growth hormone, 19 for prolactin, 18 for growth hormone and prolactin, 16 for adrenocorticotropic hormone (ACTH), and 21 cases of plurihormonal/gonadotropin adenomas were detected by immunohistochemistry. The MIB-1 antibody was positive in 139 samples and the Ki-67 index ranged from 0.16 to 15.48% (mean = 1.22 ± 2.09%), with no significant difference between genders, age groups, or secretory and non-secretory status. The Ki-67 index was higher in ACTH-secreting adenomas. Invasive pituitary adenomas had a significantly higher Ki-67 index (2.01 ± 3.15%) than macroadenomas with or without supra-sellar extension (1.12 ± 1.87%; P = 0.02). The index was not significantly different in the subgroup of adenomas with invasion of the cavernous sinus compared to groups with other types of invasion. We conclude that tumoral proliferative activity evaluated by the detection of the Ki-67 antigen is significantly higher in invasive than noninvasive adenomas, information which can be useful in therapeutic postoperative management since index cut-off values associated with aggressive behavior can be established.

Rats with high left ventricular end-diastolic pressure can be identified by Doppler echocardiography one week after myocardial infarction

The severity of left ventricular (LV) dysfunction in rats with myocardial infarction (MI) varies widely. Because homogeneity in baseline parameters is essential for experimental investigations, a study was conducted to establish whether Doppler echocardiography (DE) could accurately identify animals with high LV end-diastolic pressure as a marker of LV dysfunction soon after MI. Direct measurements of LV end-diastolic pressure were made and DE was performed simultaneously 1 week after surgically induced MI (N = 16) or sham-operation (N = 17) in female Wistar rats (200 to 250 g). The ratio of peak early (E) to late (A) diastolic LV filling velocities and the ratio of E velocity to peak early (Em) diastolic myocardial velocity were the best predictors of high LV end-diastolic pressure (>12 mmHg) soon after MI. Cut-off values of 1.77 for the E/A ratio (P = 0.001) identified rats with elevated LV end-diastolic pressure with 90% sensitivity and 80% specificity. Cut-off values of 20.4 for the E/Em ratio (P = 0.0001) identified rats with elevated LV end-diastolic pressure with 81.8% sensitivity and 80% specificity. Moreover, E/A and E/Em ratios were the only echocardiographic parameters independently associated with LV end-diastolic pressure in multiple linear regression analysis. Therefore, DE identifies rats with high LV end-diastolic pressure soon after MI. These findings have implications for using serial DE in animal selection and in the assessment of their response to experimental therapies.

Influence of depectinization in the ultrafiltration of West Indian cherry (Malpighia glabra L.) and pineapple (Ananas comosus (L.) Meer) juices

West Indian cherry (Malpighia glabra L.) and pineapple (Ananas comosus (L.) Meer)juice clarification by cross-flow UF, using polysulphone hollow fiber and ceramic tubular membranes with, respectively, nominal molecular weight cut off values of 100kDaltons and average pore diameters of 0.01mm, were studied. The influence of enzymatic treatment using enzyme concentrations of 20, 100 and 300mg/L, a time of 90min and a temperature of 40ºC for depectinization was verified. The juices were then clarified in a laboratory scale filtration unit, with an effective filtration area of 0.12m² for the polysulphone hollow fiber membrane and of 0.005m² for the ceramic tubular membranes. The influence of enzymatic treatment on viscosity, turbidity and total pectin of the juice, before ultrafiltration, is reported. Membrane performance was evaluated in terms of flow rate and clarity of the permeate. The permeate flow rate of depectinized pineapple juice was higher (30 - 60%) for both membranes. Depectinized West Indian cherry juice presented a lower permeate flow rate for the polysulphone hollow fiber membrane. The increase in permeate flow rate, with the use of the 300mg/L and 100mg/L enzyme concentration was not significant, so it is economically advantageous to ultrafilter depectinized juice, treated with an enzyme concentration of 20mg/L.

Characterization of antimicrobial resistance in Aeromonas and Vibrio isolated in Canada from fish and seafood

Plusieurs études ont examiné la sensibilité aux antimicrobiens chez les bactéries d’organismes provenant de produits issus de l’aquaculture ou de leur environnement. Aucune information n’est cependant disponible concernant la résistance aux antimicrobiens dans les bactéries de la flore de poissons ou de fruits de mer vendus au détail au Canada. C’est particulièrement vrai en ce qui a trait aux bactéries des genres Aeromonas et Vibrio, dont certaines espèces sont des agents pathogènes zoonotiques connus. Au cours de cette étude, la sensibilité aux antimicrobiens d’isolats d’Aeromonas spp. et de Vibrio spp. provenant de poissons et de crevettes domestiques et importés a été mesurée à l’aide de techniques de micro dilution en bouillon et/ou de diffusion sur disque. Les classes d’antimicrobiens examinés comprenaient les tétracyclines (TET), les inhibiteurs de la voie des folates (sulfadiméthoxine-triméthoprime, SXT), le florfenicol (FLO), et les quinolones (acide nalidixique / enrofloxacine, NA/ENO). Des valeurs seuils épidémiologiques pour Aeromonas et Vibrio ont été établies en utilisant la méthode d’interprétation normalisée des données de résistance provenant de diffusion sur disque. La recherche de gènes de résistance associés au profil de résistance des isolats a été effectuée en utilisant des PCRs et des puces ADN. Le nombre d’isolats résistants aux divers antimicrobiens parmi les 201 isolats d’Aeromonas et les 185 isolats de Vibrio étaient respectivement les suivants: TET (n=24 et 10), FLO (n=1 et 0), SXT (n=2 et 8), NA (n=7 et 5) et ENO (n= 5 et 0). Diverses associations de gènes tet(A), tet(B), tet(E), floR, sul1, sul2, et intI1 ont été détectées, les gènes tet(E), intI1, sul2 et tet(B) étant les plus communs. Les espèces d’Aeromonas et de Vibrio isolées de poissons au détail et de fruits de mer peuvent héberger une variété de gènes de résistance, bien que peu fréquemment. Le risque que représente ces gènes de résistance reste à évaluer en considérant le potentiel infectieux des bactéries, l’utilisation des ces agents antimicrobiens pour le traitement des maladies en aquaculture et en médecine humaine et leur rôle en tant que réservoir de la résistance antimicrobienne.

Revisiting youden’s index as a useful measure of the misclassification error in meta-analysis of diagnostic studies

The paper considers meta-analysis of diagnostic studies that use a continuous score for classification of study participants into healthy or diseased groups. Classification is often done on the basis of a threshold or cut-off value, which might vary between studies. Consequently, conventional meta-analysis methodology focusing solely on separate analysis of sensitivity and specificity might be confounded by a potentially unknown variation of the cut-off value. To cope with this phenomena it is suggested to use, instead, an overall estimate of the misclassification error previously suggested and used as Youden’s index and; furthermore, it is argued that this index is less prone to between-study variation of cut-off values. A simple Mantel–Haenszel estimator as a summary measure of the overall misclassification error is suggested, which adjusts for a potential study effect. The measure of the misclassification error based on Youden’s index is advantageous in that it easily allows an extension to a likelihood approach, which is then able to cope with unobserved heterogeneity via a nonparametric mixture model. All methods are illustrated at hand of an example on a diagnostic meta-analysis on duplex doppler ultrasound, with angiography as the standard for stroke prevention.

Revisiting Youden's index as a useful measure of the misclassification error in meta-analysis of diagnostic studies

The paper considers meta-analysis of diagnostic studies that use a continuous Score for classification of study participants into healthy, or diseased groups. Classification is often done on the basis of a threshold or cut-off value, which might vary between Studies. Consequently, conventional meta-analysis methodology focusing solely on separate analysis of sensitivity and specificity might he confounded by a potentially unknown variation of the cut-off Value. To cope with this phenomena it is suggested to use, instead an overall estimate of the misclassification error previously suggested and used as Youden's index and; furthermore, it is argued that this index is less prone to between-study variation of cut-off values. A simple Mantel-Haenszel estimator as a summary measure of the overall misclassification error is suggested, which adjusts for a potential study effect. The measure of the misclassification error based on Youden's index is advantageous in that it easily allows an extension to a likelihood approach, which is then able to cope with unobserved heterogeneity via a nonparametric mixture model. All methods are illustrated at hand of an example on a diagnostic meta-analysis on duplex doppler ultrasound, with angiography as the standard for stroke prevention.

Are definitions of adiposity appropriate for identification of cardiovascular disease risk in South Asian populations?

South Asian populations living in the UK have a high prevalence of the metabolic syndrome, cardiovascular disease (CVD) and type 2 diabetes which impacts greatly on the morbidity and mortality of this ethnic group. The identification of ‘at risk’ individuals is essential to initiate reventative treatment. However, this is considerably hindered by the lack of appropriate cut-off values for anthropometric measures. CVD risk is significantly higher at a lower body mass index (BMI) in many Asian groups compared with Caucasians and adiposity (particularly central deposition) is higher at similar BMI levels. The definition of adiposity in Asians needs to be firmly established and appropriate lower BMI and waist circumference cut-offs implemented in ethnic subpopulations to facilitate appropriate treatment strategies.

Validação interlaboratorial do teste de polarização fluorescente para o diagnóstico sorológico da brucelose bovina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)