Vitamin B12 Deficiency in the aged: Laboratory Diagnosis, Prevalence and Clinical Profile

B₁₂-vitamiinin puute iäkkäillä: laboratoriodiagnostiikka, yleisyys ja yhteys sairastavuuteen Tausta: B12-vitamiinin puute on yleistä iäkkäillä ja se tulisi todeta riittävän varhaisessa vaiheessa palautumattomien vaurioiden estämiseksi. On epäselvää pitäisikö diagnostiikka kohdistaa tiettyihin riskiryhmiin vai mahdollisesti seuloa valikoimatonta vanhusväestöä. Myöskään yksimielisyyttä laboratoriotutkimusten valinnasta ei ole. Tavoitteet: Tutkimuksen tarkoituksena oli evaluoida uutta HoloTC RIA menetelmää ja tuottaa viitearvot sille, selvittää B12-vitamiinin puutteen yleisyys, yhteys sairastavuuteen ja mahdolliset riskitekijät suomalaisessa vanhusväestössä, arvioida munuaisfunktion vaikusta B12-vitamiinin puutteen laboratoriotutkimuksiin ja näiden perusteella ehdottaa suomalaiseen terveydenhuoltoon sopivaa laboratoriotutkimusstrategiaa. Aineisto ja menetelmät: Liedon iäkkäät -tutkimuksen vanhusaineisto on edustava otos yhden kunnan yli 65-vuotiaasta väestöstä, yhteensä 1260 henkilöä. Tutkittavat kävivät lääkärintarkastuksessa, ja heistä on käytettävissä runsaasti laboratoriotutkimuksia sekä tiedot sairauksista, ruokavaliosta, lääkkeiden ja vitamiinivalmisteiden käytöstä, dementiaseula ja depressiokysely. Viitearvoaineistoa varten kerättiin näytteet 84 vapaaehtoisesta terveestä aikuisesta ja menetelmäevaluaatiota varten 107 sairaalapotilaasta. Tulokset: HoloTC RIA menetelmän toistettavuus oli hyvä manuaalimenetelmäksi. 95%:n viiteväli holotranskobalamiinille oli 37-171 pmol/l. Kaikilla tutkittavilla, joilla oli muilla laboratoriotutkimuksilla osoitettu todennäköinen B12-vitamiinin puute, myös holotranskobalamiini oli viitealueen alarajaa pienempi. Suurentuneella kystatiini C-pitoisuudella osoitettu munuaisten vajaatoiminta korreloi voimakkaasti homokysteiinin (rs=0.53, p<0.001) ja metyylimalonihapon (rs=0.27, p<0.001) pitoisuuksiin, mutta ei kokonais-B12-vitamiinin (rs=- 0.04, p=0.227) tai holotranskobamiinin (rs=-0.01, p=0.817) pitoisuuksiin. Suomalaisessa vanhusväestössä B12-vitamiinin puutteen prevalenssi oli 12%. Kokonais- B12-vitamiinin pitoisuus oli matala (<150 pmol/l) 6%:lla. Miessukupuoli (OR 1.9, 95% CI 1.2-2.9), ikä ≥75 (OR 2.2, 95% CI 1.4-3.4) ja maitotuotteiden välttäminen (OR 2.3, 95% CI 1.2-4.4) lisäsivät B12-vitamiinin puutteen riskiä, mutta anemia (OR 1.3, 95% CI 0.7-2.3) tai makrosytoosi (OR 1.2, 95% CI 0.6-2.7) eivät. Päätelmät: Diagnosoimaton B12-vitamiinin puute on yleistä iäkkäillä, mutta kliinisesti merkityksellistä spesifistä riskiryhmää ei löydy. Koska anemian ja makrosytoosin puuttuminen ei poissulje B12-vitamiinin puutetta ja munuaisten vajaatoiminta heikentää metabolisten merkkiaineiden käyttökelpoisuutta, kokonais-B12-vitamiinia suositellaan ensisijaiseksi laboratoriotutkimukseksi epäiltäessä B12-vitamiinin puutetta ja tarvittaessa varmentavina tutkimuksina käytetään homokysteiiniä ja holotranskobalamiinia.

Mitochondrial disease in Southwestern Finland. Population-based molecular genetic and clinical studies

Mitochondria are present in all eukaryotic cells. They enable these cells utilize oxygen in the production of adenosine triphosphate in the oxidative phosphorylation system, the mitochondrial respiratory chain. The concept ‘mitochondrial disease’ conventionally refers to disorders of the respiratory chain that lead to oxidative phosphorylation defect. Mitochondrial disease in humans can present at any age, and practically in any organ system. Mitochondrial disease can be inherited in maternal, autosomal dominant, autosomal recessive, or X-chromosomal fashion. One of the most common molecular etiologies of mitochondrial disease in population is the m.3243A>G mutation in the MT-TL1 gene, encoding mitochondrial tRNALeu(UUR). Clinical evaluation of patients with m.3243A>G has revealed various typical clinical features, such as stroke-like episodes, diabetes mellitus and sensorineural hearing loss. The prevalence and clinical characteristics of mitochondrial disease in population are not well known. This thesis consists of a series of studies, in which the prevalence and characteristics of mitochondrial disease in the adult population of Southwestern Finland were assessed. Mitochondrial haplogroup Uk was associated with increased risk of occipital ischemic stroke among young women. Large-scale mitochondrial DNA deletions and mutations of the POLG1 gene were the most common molecular etiologies of progressive external ophthalmoplegia. Around 1% of diabetes mellitus emerging between the ages 18 – 45 years was associated with the m.3243A>G mutation. Moreover, among these young diabetic patients, mitochondrial haplogroup U was associated with maternal family history of diabetes. These studies demonstrate the usefulness of carefully planned molecular epidemiological investigations in the study of mitochondrial disorders.

Bariatric and Post-Bariatric Surgery: from Metabolic Surgery to Plastic Surgery Indications

Background: Controversy exists concerning indications and outcomes of major bariatric surgery procedures. Massive weight loss after bariatric surgery leads to excess skin with functional and aesthetic impairments. The aim of this study was to investigate the major bariatric surgery procedures and their outcomes in two specific subgroups of morbidly obese patients, ≥55-year-olds and the superobese. Further aims were to evaluate whether the preoperative weight loss correlates with laparoscopic gastric bypass complications. The prevalence and impact of excess skin and the desire for body contouring after bariatric surgery were also studied. Patients and Methods: Data from patients who underwent Laparoscopic Adjustable Gastric Banding (LAGB) and Laparoscopic Roux-en-Y Gastric Bypass (LRYGB) at Vaasa Central Hospital were collected and postoperative outcomes were evaluated according to the BMI, age and preoperative weight loss. Patients who had undergone bariatric surgery procedures were asked to complete a questionnaire to estimate any impairment due to redundant skin and to analyse each patient’s desire for body contouring by area. Results: No significant difference was found in operative time, hospital stay, or overall early postoperative morbidity between LAGB and LRYGB. Mean excess weight loss percents (EWL%) at 6 and 12 months after LRYGB were significantly higher. A significant difference was found in operative time favouring patients <55 years. Intraoperative complications were significantly more frequent in the group aged >55 years. No significant difference was detected in overall postoperative morbidity rates. A significant difference was found in operative time and hospital stay favouring all patients who lost weight preoperatively. Most patients reported problems with redundant skin, especially on the abdomen, upper arms and rear/buttocks, which impaired daily physical activity in half of them. Excess skin was significantly associated with female gender, weight loss and ΔBMI. Patients with a WL >20 kg, ΔBMI ≥10 kg/m2 and an EWL % > 50 showed a significantly surplus skin discomfort (p < 0.001). Most patients desired body contouring surgery, with high or very high desire for waist/abdomen (62.2%), upper arm (37.6%), chest/breast (28.3%), and rear/buttock (35.6%) contouring. Conclusions: LRYGB is effective and safe in superobese (BMI >50) and elderly (>55 years) patients. A preoperative weight loss >5% is recommended to improve the outcomes and reduce complications. A WL >20 kg, ΔBMI ≥10 kg/m2 and an EWL % > 50 are associated with a higher functional discomfort due to redundant skin and to a stronger desire for body contouring plastic surgery.

Analytic evaluation of three-phase short circuit demagnetization and hysteresis loss risk in rotor-surface-magnet Permanent-Magnet Synchronous Machines

Permanent magnet synchronous machines (PMSM) have become widely used in applications because of high efficiency compared to synchronous machines with exciting winding or to induction motors. This feature of PMSM is achieved through the using the permanent magnets (PM) as the main excitation source. The magnetic properties of the PM have significant influence on all the PMSM characteristics. Recent observations of the PM material properties when used in rotating machines revealed that in all PMSMs the magnets do not necessarily operate in the second quadrant of the demagnetization curve which makes the magnets prone to hysteresis losses. Moreover, still no good analytical approach has not been derived for the magnetic flux density distribution along the PM during the different short circuits faults. The main task of this thesis is to derive simple analytical tool which can predict magnetic flux density distribution along the rotor-surface mounted PM in two cases: during normal operating mode and in the worst moment of time from the PM’s point of view of the three phase symmetrical short circuit. The surface mounted PMSMs were selected because of their prevalence and relatively simple construction. The proposed model is based on the combination of two theories: the theory of the magnetic circuit and space vector theory. The comparison of the results in case of the normal operating mode obtained from finite element software with the results calculated with the proposed model shows good accuracy of model in the parts of the PM which are most of all prone to hysteresis losses. The comparison of the results for three phase symmetrical short circuit revealed significant inaccuracy of the proposed model compared with results from finite element software. The analysis of the inaccuracy reasons was provided. The impact on the model of the Carter factor theory and assumption that air have permeability of the PM were analyzed. The propositions for the further model development are presented.

Quantification of Toxin Biosynthesis Genes In Cyanobacteria and Dinoflagellates - Genetic Factors as Predictors of Toxin Production in the Environment

Harmful algal blooms (HABs) are events caused by the massive proliferation of microscopic, often photosynthetic organisms that inhabit both fresh and marine waters. Although HABs are essentially a natural phenomenon, they now cause worldwide concern. Recent anthropogenic effects, such as climate change and eutrophication via nutrient runoff, can be seen in their increased prevalence and severity. Cyanobacteria and dinoflagellates are often the causative organisms of HABs. In addition to adverse effects caused by the sheer biomass, certain species produce highly potent toxic compounds: hepatotoxic microcystins are produced exclusively by cyanobacteria and neurotoxic saxitoxins, also known as paralytic shellfish toxins (PSTs), by both cyanobacteria and dinoflagellates. Specific biosynthetic genes in the cyanobacterial genomes direct the production of microcystin and paralytic shellfish toxins. Recently also the first paralytic shellfish toxin gene sequences from dinoflagellate genomes have been elucidated. The public health risks presented by HABs are evident, but the monitoring and prediction of toxic events is challenging. Characterization of the genetic background of toxin biosynthesis, including that of microcystins and paralytic shellfish toxins, has made it possible to develop highly sensitive molecular tools which have shown promise in the monitoring and study of potentially toxic microalgae. In this doctoral work, toxin-specific genes were targeted in the developed PCR and qPCR assays for the detection and quantification of potentially toxic cyanobacteria and dinoflagellates in the environment. The correlation between the copy numbers of the toxin biosynthesis genes and toxin production were investigated to assess whether the developed methods could be used to predict toxin concentrations. The nature of the correlation between gene copy numbers and amount of toxin produced varied depending on the targeted gene and the producing organism. The combined mcyB copy numbers of three potentially microcystin-producing cyanobacterial genera showed significant positive correlation to the observed total toxin production. However, the presence of PST-specific sxtA, sxtG, and sxtB genes of cyanobacterial origin was found to be a poor predictor of toxin production in the studied area. Conversely, the dinoflagellate sxtA4 was a good qualitative indicator of a neurotoxic bloom both in the laboratory and in the field, and population densities reflected well the observed toxin concentrations. In conclusion, although the specificity of each potential targeted toxin biosynthesis gene must be assessed individually during method development, the results obtained in this doctoral study support the use of quantitative PCR -based approaches in the monitoring of toxic cyanobacteria and dinoflagellates.

Clinical and genetic markers in disease progression – a study among subjects with obstructive lung diseases

Asthma, COPD, and asthma and COPD overlap syndrome (ACOS) are chronic pulmonary diseases with an obstructive component. In COPD, the obstruction is irreversible and the disease is progressive. The aim of the study was to define and analyze factors that affected disease progression and patients’ well-being, prognosis and mortality in Chronic Airway Disease (CAD) cohort. The main focus was on COPD and ACOS patients. Retrospective data from medical records was combined with genetic and prospective follow-up data. Smoking is the biggest risk factor for COPD and even after the diagnosis of the disease, smoking plays an important role in disease development and patient’s prognosis. Sixty percent of the COPD patients had succeeded in smoking cessation. Patients who had managed to quit smoking had lower mortality rates and less psychiatric diseases and alcohol abuse although they were older and had more cardiovascular diseases than patients who continued smoking. Genetic polymorphism rs1051730 in the nicotinic acethylcholine receptor gene (CHRNA3/5) associated with heavy smoking, cancer prevalence and mortality in two Finnish independent cohorts consisting of COPD patients and male smokers. Challenges in smoking cessation and higher mortality rates may be partly due to individual patient’s genetic composition. Approximately 50% of COPD patients are physically inactive and the proportion was higher among current smokers. Physically active and inactive patients didn’t differ from each other in regard to age, gender or comorbidities. Bronchial obstruction explained inactivity only in severe disease. Subjective sensation of dyspnea, however, had very strong association to inactivity and was also associated to low health related quality of life (HRQoL). ACOS patients had a significantly lower HRQoL than either the patients with asthma or with COPD even though they were younger than COPD patients, had better lung functions and smaller tobacco exposure.