published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Μελετήθηκαν επιδηµιολογικές, κλινικές, βιοχηµικές, ιολογικές και ανοσολογικές παράµετροι σε ασθενείς αιµοκαθαιρόµενους για χρόνια νεφρική ανεπάρκεια µε HCV λοίµωξη και συγκρίθηκαν µε τις αντίστοιχες παραµέτρους HCV µολυνθέντων ασθενών µε φυσιολογική νεφρική λειτουργία. 1) Η µελέτη µας έδειξε ότι οι αιµοκαθαιρόµενοι ασθενείς µε HCV λοίµωξη είχαν σηµαντικά µικρότερες τιµές αµινοτρανσφερασών από αυτούς που είχαν φυσιολογική νεφρική λειτουργία. Από αυτό συµπεραίνεται ότι στους αιµοκαθαιρόµενους, για να εκτιµηθούν οι αµινοτρανσφεράσες σαν βιοχηµικοί δείκτες της ηπατίτιδας C θα πρέπει να διορθώνονται όσον αφορά την υποαµινοτρανσφερασαιµία των αιµοδιυλιζοµένων. 2) Οι αιµοδιυλιζόµενοι είχαν χαµηλότερο ιικό φορτίο από τους ασθενείς µε φυσιολογική νεφρική λειτουργία, σε αντίθεση µε άλλους ανοσοκατεσταλµένους ασθενείς που παρουσιάζουν υψηλότερο ιικό φορτίο από τους ανοσοϊκανούς µε HCV λοίµωξη. Με το χαµηλότερο ιικό φορτίο πιθανώς συσχετίζεται ο µικρότερος βαθµός νεκροφλεγµονώδους δραστηριότητας που ανευρέθη στην βιοψία του ήπατος αυτών των ασθενών. 3) Η συχνότητα κρυοσφαιριναιµίας των αιµοκαθαιροµένων ασθενών δεν διέφερε από αυτών µε φυσιολογική νεφρική λειτουργία, αλλά οι αιµοκαθαιρόµενοι παρουσίαζαν µικρότερες τιµές κρυοκρίτη και κανείς εξ αυτών δεν εµφάνισε κλινικό σύνδροµο κρυοσφαιριναιµίας. Επίσης η συχνότητα ανευρέσεως θετικού ρευµατοειδούς παράγοντος ήταν µικρότερη ενώ τα επίπεδα του C4 κλάσµατος του συµπληρώµατος ήταν υψηλότερα στους αιµοκαθαιρόµενους ασθενείς. Αυτά τα ευρήµατα υποδηλώνουν σχετική ανεπάρκεια του µηχανισµού δηµιουργίας αυτοαντισωµάτων και ανοσοσυµπλεγµάτων στους αιµοκαθαιρόµενους ασθενείς. 4) Οι αιµοδιυλιζόµενοι ασθενείς µε HCV λοίµωξη παρουσίαζαν ξηρά κερατοεπιπεφυκίτιδα σε παρόµοιο ποσοστό µε τους HCV ασθενείς µε φυσιολογική νεφρική λειτουργία, αλλά η ανοσολογική αντίδραση των δακρυικών αδένων έναντι του ιού της ηπατίτιδας C ήταν µάλλον µικρότερη. Η ξηρά κερατοεπιπεφυκίτιδα στους ασθενείς µε HCV λοίµωξη έδειξε να συνδυάζεται µε µεγάλη ηλικία και µεγαλύτερο στάδιο ηπατικής ίνωσης. 5) Τέλος, οι αιµοκαθαιρόµενοι ασθενείς ανευρέθησαν να έχουν µικρότερο βαθµό νεκροφλεγµονώδους δραστηριότητας και ίνωσης από τους ασθενείς µε φυσιολογική νεφρική λειτουργία και πιθανώς µάλιστα ηπιώτερη νόσο όσον αφορά όλες τις παραµέτρους αυτής. / We studied epidemiological, clinical, biochemical, virological and immunological characteristics of HCV infected patients on chronic hemodialysis for end stage renal failure and we compared them to those of otherwise normal patients with chronic HCV infection. 1) Our study showed that the mean values of aminotransferases were significantly lower in hemodialysis patients compared to patients with normal renal function. Our data suggest that in patients undergoing hemodialysis aminotransferases levels should be interpreted, for evaluation of hepatitis C activity, after correction for hypoaminotransferasemia of the hemodialysis population. 2) HCV viral load was found significantly lower in patients on maintenance hemodialysis than in the group with normal renal function. This contrasts with the high HCV viral load that is usually found in other immunocompromised patients. The lower grading of necroinflammatory activity, which was found in liver biopsy samples of hemodialysis patients, is possibly related to the lower viral load in these patients. 3) Prevalence of cryoglobulinemia in HCV-infected hemodialysis patients was not different from that of patients with normal renal function, but hemodialysis patients had lower cryocrit values and none of them presented a cryoglobulinemic syndrome. Rheumatoid factor positivity rate was also lower in hemodialysis group, while complement C4 levels were higher in these patients. These findings denote less efficient mechanism of creating autoantibodies and immune complexes in this population. 4) Patients on hemodialysis infected with HCV have a similar percentage of keratoconjunctivitis sicca with normal renal function HCV patients. Nevertheless hepatitis C virus appears to incite lower immunologic response to lacrimal glands in uremic as opposed to otherwise normal patients. Keratoconjunctivitis sicca in patients with chronic HCV infection was associated with older age and higher staging score of fibrosis in liver biopsy. 5) Finally, hemodialysis patients were found to have lower grading and staging score than those with normal renal function and possibly less severe disease from every aspect.

Confocal microendoscopy provides real-time high resolution cellular level images via a minimally invasive procedure. Results from an ongoing clinical study to detect ovarian cancer with a novel confocal fluorescent microendoscope are presented. As an imaging modality, confocal fluorescence microendoscopy typically requires exogenous fluorophores, has a relatively limited penetration depth (100μm), and often employs specialized aperture configurations to achieve real-time imaging in vivo. Two primary research directions designed to overcome these limitations and improve diagnostic capability are presented. Ideal confocal imaging performance is obtained with a scanning point illumination and confocal aperture, but this approach is often unsuitable for real-time, in vivo biomedical imaging. By scanning a slit aperture in one direction, image acquisition speeds are greatly increased, but at the cost of a reduction in image quality. The design, implementation, and experimental verification of a custom multi-point-scanning modification to a slit-scanning multi-spectral confocal microendoscope is presented. This new design improves the axial resolution while maintaining real-time imaging rates. In addition, the multi-point aperture geometry greatly reduces the effects of tissue scatter on imaging performance. Optical coherence tomography (OCT) has seen wide acceptance and FDA approval as a technique for ophthalmic retinal imaging, and has been adapted for endoscopic use. As a minimally invasive imaging technique, it provides morphological characteristics of tissues at a cellular level without requiring the use of exogenous fluorophores. OCT is capable of imaging deeper into biological tissue (~1-2 mm) than confocal fluorescence microscopy. A theoretical analysis of the use of a fiber-bundle in spectral-domain OCT systems is presented. The fiber-bundle enables a flexible endoscopic design and provides fast, parallelized acquisition of the optical coherence tomography data. However, the multi-mode characteristic of the fibers in the fiber-bundle affects the depth sensitivity of the imaging system. A description of light interference in a multi-mode fiber is presented along with numerical simulations and experimental studies to illustrate the theoretical analysis.

The first real-time uorescence confocal microlaparoscope has been de- veloped that provides instant in vivo cellular images, comparable to those provided by histology, through a nondestructive procedure. The device in- cludes an integrated contrast agent delivery mechanism and a computerized depth scan system. The instrument uses a fiber bundle to relay the image plane of a slit-scan confocal microlaparoscope into tissue. The confocal laparoscope was used to image the ovaries of twenty-one patients in vivo using uorescein sodium and acridine orange as the uorescent contrast agents. The results indicate that the device is safe and functions as designed. A Monte Carlo model was developed to characterize the system performance in a scattering media representative of human tissues. The results indicate that a slit aperture has limited ability to image below the surface of tissue. In contrast, the results show that multi-pinhole apertures such as a Nipkow disk or a linear pinhole array can achieve nearly the same depth performance as a single pinhole aperture. The model was used to determine the optimal aperture spacing for the multi-pinhole apertures. The confocal microlaparoscope represents a new type of in vivo imaging device. With its ability to image cellular details in real time, it has the potential to aid in the early diagnosis of cancer. Initially, the device may be used to locate unusual regions for guided biopsies. In the long term, the device may be able to supplant traditional biopsies and allow the surgeon to identify early stage cancer in vivo.

One in eight women in America will develop breast cancer at some point in their lives. Breast cancer is the second deadliest form of cancer for women in the United States. When a suspicious region of the breast is detected, the tissue is diagnosed by removing a sample, preparing an H&E section, and performing histopathology. This procedure is expensive, invasive, and can take days to return a diagnosis. An alternative to excision biopsies is to instead perform an optical biopsy. This work details endomicroscopes intended to perform optical biopsies in breast tissue. The work address two issues limiting current optical biopsy systems: insufficient resolution and inability to reject out of focus light. To improve the resolution of current endomicroscopes, ultra-slim objectives are developed using optical plastics and zero alignment fabrication techniques. These objectives can outperform current alternative endomicroscope objectives in terms of performance across the field of view and chromatic aberration correction, while remaining as narrow as a biopsy needle. Next, an endomicroscope which utilizes structured illumination to perform optical section is designed, tested, and evaluated on ex vivo breast biopsies. The new endomicroscope provides high contrast images by reducing out of focus background light. Finally, an achromatic, ultra-slim objective and the structured illumination endomicroscope are integrated to form an optical biopsy system with improved lateral resolution and axial response. This integrated system is a step forward for in vivo microscopy and cancer diagnoses.

Research can conflict with conservation when invasive techniques are used on protected animal species. We developed a decision framework including the research question, the choice of technique, and the recommended course of action following the evaluation of the risks and benefits. This evaluation includes biological risks and benefits and considerations linked to the perception of resource users. We applied this framework a posteriori to a case study, the use of biopsy sampling on St. Lawrence belugas. We monitored the biological risks and benefits over four field seasons using behavioural and physiological indices and reports on the work in progress. We evaluated the risks as "low" and the benefits as "medium". For benefits to outweigh risks, procedures to minimise risks, publication of the work, and formulation of recommendations for conservation are essential. Researchers should be prepared to discuss with stakeholders the potential conflicts between their projects and conservation.

This study was aimed at investigating adverse and beneficial long-term effects of jejunoileal bypass (JIB) sugery in obese patients. The JIB was the first widly used surgical procedure for treatment of morbid obesity. The weight loss was remarkable, but the procedure was declared not appropiate for obesity surgery in the late 1970's. Serious late adverse effects such as liver cirrhosis and malignancies, have been postulated. Unexpectedly few studies have adressed these problems. In the long-term follow-up of 87 uniformly operated patients, several persisting beneficial effects were found. The mean Body Mass Index was 41.5 kg/m2 at the time of operation and 29.7 kg/m2 sixteen years after the operation. Diabetes type II and hyperlipidemia, common in an obese population, was not found in this group. Reversals were performed in 3% of the patients in contrast to 20-30% in many earlier studies. Revisions performed in 8% of the patients due to excessive weight loss could have contributed to the good long-term outcome. Percutaneous liver biopsies from 44 patients taken 14-20 (mean 17) years after JIB revealed normal or fatty liver, a lower degree of histological abnormalities than in 11 biopsies taken at the time of operations 1-14 (mean 6) years postoperatively. Liver cirrhosis seen early in one patient could not be found in the late biopsies. Reduced activity of the fibrinolytic system has been shown to be a new cardiovacular risk factor. In 45 patients studied 14-20 years after JIB, the levels of both plasminogen activator inhibitor type 1 (PAI-1) and tissue plasminogen activator (tPA) were significantly lower than in a control group of 10 morbidly obese patients ( PAI-1: 8.4 vs 32 U/mL, tPA: 7.2 vs 12 pg/L). Bile acids are regarded as cofactors in the carcinogenesis in the colon and experimentally an increased frequency of malignant tumors has been demonstated after JIB in carcinogen-induced rats. In 30 of the operated patients, colonoscopy with biopsy was performed 11-17 yeras after the operation. No evidence for malignant transformation was found as reflected by an abscense of polyp formation, histologic dysplasia or aneuploidia in flow cytometric DNA analysis. Eight hundred and thirty patients from 10 hospitals subjected to JIB were compared to 1660 controls with respect to malignant diagnosis over a 20 years period. No significantly increased risk for colorectal carcinoma could be demonstrated. However the overall risk for malignant disease was increased in the operated patients. The frequency of endometrial carcinoma was significantly elevated up to five years after the operation but was normal after that time. In conclusion the postulated progress of serious adverse effects of JIB such as liver cirrhosis and malignant disease has not been possible to demonstrate. Several beneficial effects such as weight loss and reduction of cardiovascular risk factors have been found a long time after the operation. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1995, härtill 5 uppsatser.</p> / digitalisering@umu

Background: Transrectal ultrasound is commonly performed in the clinical evaluation of the prostate. Ultrasound-guided randomized sextant biopsy became the standard procedure for the diagnosis of carcinoma of the prostate (CaP). A guided biopsy of sonographically irregular lesions of the prostate is not performed in randomized biopsies. An almost generally accepted opinion is that hypoechoic lesions are suspicious for the presence of CaP. However, the role of prostatic lesions with an echogenicity other than iso- or hypoechoic, e.g. hyperechoic or irregular lesions in relation to CaP is not clear. The intention of the present prospective study was to clarify the role of different prostatic ultrasound findings with a new-generation ultrasound probe in regard to their relevance concerning the presence of cancer. Material and Methods: 265 patients who were referred for prostatic evaluation because of an elevated PSA serum level or a positive digital rectal examination were enrolled in a prospective study. All patients had a systematic ultrasound-guided sextant biopsy of the prostate and a 4-core biopsy of the transition zone. All biopsy cores taken were guided by transrectal ultrasound. In case of a sonographically suspicious lesion, biopsy was always directed into this area. The predominant ultrasound appearance was separately recorded for each core. Results: Carcinoma of the prostate was detected in 87 (32.8%) of the 265 patients. Biopsy cores with isoechoic ultrasound findings revealed CaP in 7.6%. The data for hypoechoic, hyperechoic, mixed-echoic and anechoic lesions were 34.5, 26.9, 21.1 and 0%, respectively. Hypoechoic ultrasound findings were less frequently found in the transition zone of the prostate, but the rate of CaP detection was the same as in the peripheral zone of the prostate. Conclusions:The transrectal ultrasound pattern of the prostate yields important information about the presence of carcinoma of the prostate. Especially hypoechoic lesions indicate the presence of CaP in a significant proportion of cases. However, hyperechoic lesions and lesions of mixed or irregular echogenicity were found to contain cancer in significant numbers as well, and should therefore be considered to be suspicious for cancer when performing transrectal ultrasound of the prostate. Directed biopsy of irregular ultrasound patterns in the prostate seems therefore to be recommendable. / Hintergrund: Der transrektale Ultraschall ist die häufigste bildgebende Untersuchung zur klinischen Beurteilung der Prostata. Zur Diagnostik des Prostatakarzinoms (PCa) hat sich die ultraschallgesteuerte Sextanten-Biopsie als Standardverfahren etabliert. Eine gezielte Biopsie irregulärer Ultraschallbezirke ist hier nicht vorgesehen. Es ist jedoch bekannt, daß sonographisch echoarm erscheinende Areale suspekt für die Präsenz eines PCa sind. Die Wertigkeit nicht einheitlicher oder echoreicher Ultraschallmuster ist jedoch bisher nicht zweifelsfrei geklärt. Ziel der vorliegenden Arbeit war es, mit einem Ultraschallgerät der neuesten Generation die Bedeutung der verschiedenen Ultraschallmuster bezüglich des Vorhandenseins von Prostatakarzinomen zu klären. Material und Methoden: 265 Patienten mit erhöhten PSA-Serumwerten oder suspekten Tastbefunden der Prostata wurden in die prospektive Untersuchung eingeschlossen. Bei allen Patienten wurden systematische, ultraschallgesteuerte Prostatabiopsien, wie in der Sextantenbiopsie vorgesehen, und 4 Zylinder aus der Transitionalzone entnommen. Bei der Biopsie wurde jedoch gezielt die Punktion in Bereichen von – falls vorhanden – irregulärem Ultraschallmuster vorgenommen und das entsprechende Ultraschallbild dokumentiert. Ergebnisse: Bei 87 der 265 Patienten (32,8%) wurden Prostatakarzinome nachgewiesen. Biopsiezylinder aus isodensen Bereichen wiesen in 7,6% ein Prostatakarzinom auf. Die Karzinomhäufigkeit bei Biopsie von echoarmen und echoreichen Arealen sowie von Arealen mit unterschiedlichen Echomustern und von zystischen Arealen wurde mit 34,5, 26,9, 21,1 bzw. 0% ermittelt. Echoarme Befunde wurden seltener in der Transitionalzone nachgewiesen, waren jedoch dort in etwa gleicher Häufigkeit mit einem Karzinom verbunden wie in der peripheren Zone. Schlußfolgerungen: Das transrektale Ultraschallmuster in der Prostata liefert wichtige Hinweise auf das Vorhandensein eines Prostatakarzinoms. Insbesondere echoarme Läsionen deuten auf ein PCa hin. Echoreiche Läsionen und solche mit unterschiedlichen Echomustern enthielten jedoch Karzinome in so bedeutender Anzahl, daß diese Läsionen ebenfalls als karzinomverdächtig eingestuft werden müssen und auch eine gezielte Biopsie dieser Areale im Rahmen der Sextantenbiopsie empfehlenswert erscheint. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Bakteriologinis nudegimo žaizdų tyrimas svarbus nustatant esamus potencialius patogenus, padeda diagnozuoti infekciją, leidžia įvertinti sepsio tikimybę, nustatyti tinkamą laiką žaizdos audinių rekonstrukcijai. Tačiau iki dabar tęsiasi diskusijos, kuris mėginio paėmimo metodas yra optimalus žaizdos mikroflorai arba infekcijai nustatyti. Lietuvoje toks tyrimas iki šiol nebuvo atliktas, o kitų šalių mokslininkų skelbiami rezultatai gana prieštaringi. Atlikto darbo metu tyrėme, kuris bakteriologinio tyrimo metodas (kiekybinis bei pusiau kiekybinis tepinėliai ar biopsija) yra kliniškai vertingiausias žaizdos mikrofloros stebėjimui ligos periodu, infekcijos patvirtinimui atsižvelgiant į klinikinius žaizdos pokyčius. Vienodas bakterijų rūšis tose pačiose žaizdose dažniausiai nustatė biopsija ir pusiau kiekybinis tepinėlis. Šių metodų bendras rezultatų sutapimas buvo labai geras. Abiem metodais nustatomo bakterijų kiekio koreliacija – vidutinė. Tačiau geriausiai rezultatai sutapo žaizdoje esant nedideliam bakterijų kiekiui. Esant klinikiniams žaizdos infekcijos požymiams reikšmingai dažniau bakterijos ir didesnis jų rūšių kiekis nustatytas biopsijos tiriamojoje medžiagoje. Biopsijos metodu reikšmingai dažniau nustatytas labai gausus (>105 KFV) bakterijų kiekis. Nudegimo žaizdų užteršimui bakterijomis stebėti, kai nėra infekcijos požymių, pusiau kiekybinis tepinėlio metodas yra tinkamiausias. Kliniškai nustatytą žaizdos infekciją geriausiai atspindi biopsijos tyrimo rezultatai. / Evaluation of microorganisms in burn wound is important not only in determining potential pathogens present, but also allows diagnosing an infection, evaluating possibility of sepsis, and determining the appropriate time for wound tissue reconstruction. However, there are still many discussions about the optimal wound sample taking method to determine wound microflora or infection, and the opinions about sample taking methods for identification of microorganisms are controversial. We have compared three methods (quantitative swab, semi-quantitative swab, biopsy) and determined significant differences. Similar species of bacteria in the same wounds were most frequently identified by biopsy and the semi-quantitative swab method. The general concordance of the results of these methods was very good. There was a medium correlation of the bacterial amount identified by these methods. However, there was the best concordance of the results in presence of a small amount of bacteria in a wound.In presence of clinical wound infection signs, bacteria and larger number of their species were significantly more frequently identified in the biopsy material. The biopsy method significantly more frequently identified a very large amount (>105 CFU) of bacteria. The semi-quantitative swab method is most appropriate to monitor burn wound contamination with bacteria when there are no infection signs. A clinically determined wound infection was best reflected by the results of biopsy.

Objectives: Intact cell peptidome profiling (ICPP) with MALDI-ToF Mass-Spectrometry holds promise as a non invasive method to detect head and neck squamous cell carcinoma (HNSCC) objectively, which may improve the early diagnosis of oral cancer tremendously. The present study was designed to discriminate between tumour samples and non-cancer controls (healthy mucosa and oral lesions) by analysing complete spectral patterns of intact cells using MALDI-ToF MS. Material and Methods: In the first step, a data base consisting of 26 patients suffering from HNSCC was established by taking brush biopsy samples of the diseased area and of the healthy buccal mucosa of the respective contralateral area. After performing MALDI-ToF MS on these samples, classification analysis was used as a basis for further classification of the blind study composed of additional 26 samples including HNSCC, oral lesions and healthy mucosa. Results: By analyzing spectral patterns of the blind study, all cancerous lesions were defined accurately. One incorrect evaluation (false positive) occurred in the lesion cohort, leading to a sensitivity of 100%, a specificity of 93% and an overall accuracy of 96.5%. Conclusion: ICPP using MALDI-ToF MS is able to distinguish between healthy and cancerous mucosa and between oral lesions and oral cancer with excellent sensitivity and specificity, which may lead to a more impartial early diagnosis of HNSCC.