Monitoring microvascular free flaps with tissue oxygen measurement and pet

Snoring occurs as a major symptom in patients with sleep disordered breathing (SDB). The aetiology of snoring remains still unclear despite various attempts to localize snoring. The correlation between different snoring sounds and the severity of SDB has not yet been investigated in a larger population. The aim of this study was to record and analyse snoring sounds and to correlate the obtained data with clinical and polysomnographical parameters. Sixty male patients with suspected SDB and reported snoring underwent a clinical examination and night time polysomnography. The parallel digitally recorded snoring sounds were analysed by fast fourier transformation (FFT). Peak intensity was determined from the power spectrum. The periodicity of snoring was classified into rhythmic and non-rhythmic snoring according to the presence of air flow interruptions due to obstructive apneas. Patients with primary snoring revealed peak intensities between 100 and 300 Hz. Patients with an obstructive sleep apnea syndrome (OSAS) revealed peak intensities above 1,000 Hz. Polysomnographical data (AHI, mean and minimum SpO₂) as well as body mass index (BMI) correlated with peak intensity of the power spectrum. None of the parameters of the clinical examination correlated with peak intensity. Frequency analysis of snoring sounds provides a useful diagnostic tool to distinguish between different patterns of snoring and respective SDB. The topodiagnosis of snoring is not possible by means of frequency analysis or clinical examination alone. Acoustical analysis of snoring sounds seems a promising additional diagnostic tool to verify different types of SDB in snoring patients.     

A comparison of static and dynamic calibration techniques for the vestibulo-ocular reflex signal

We investigated two calibration techniques commonly used with eye movement signals pertaining to the vestibulo-ocular reflex. Eye movement signals were recorded electro-oculographically as usual and calibrated using both static and dynamic calibration techniques. The calibration values of normals and patients were computed and compared to each other. Also gain parameters of vestibulo-ocular reflex which depend on the calibration were computed. We found that both techniques are chiefly equally valid, and there are no considerable differences in results computed with either one.     

Second Derivative of Developed Tension in Classifying Cardiotonics with Respect to Their Mechanisms of Action: Drugs Affecting cAMP Metabolism

Abstract: The second derivative of developed tension (T”, d²T/dt²) has not come into common use in the analysis of cardiac contractility, although it has been shown to give additional information on the myocardial contraction-relaxation cycle (CRC). In the present study a new way to use T”in the analysis of myocardial mechanics, including the time course of T”, is described. Profiles of the T”of the some drugs with established cardiotonic effects are presented. Experiments were carried out in spontaneously beating whole rat atria preparations. The effects of changing contraction frequency on the measured parameters were studied with electrically paced left atria. Qualitative inotropic effects of 1-methyl-3-isobutylxanthine (MIX), theophylline, caffeine, milrinone, isoprenaline and forskolin were studied. Concentrations equief-fective with respect to the force of contraction were tested. Inotropic profiles were evaluated at the time of maximal force of contraction. We found that methylxanthines have a mechanical behaviour quite distinct from other inotropic agents acting via cAMP. The effects of MIX were similar to those of theophylline in all respects. A tendency to increase the active relaxation phase of T”was a property common to methylxanthines. Caffeine also prolonged the phases of contraction, whereas MIX and theophylline have opposite effects. Milrinone in turn mimics the effects of isoprenaline and forskolin; abbreviation of the relaxation phase of T”was the feature most typical of them. Caffeine was the only agent which did not shorten the duration of CRC. The method proved valuable in basic research on drug effects on cardiac contractility.     

Comprehensive characterization of HNPCC-related colorectal cancers reveals striking molecular features in families with no germline mismatch repair gene mutations

A considerable fraction of families with HNPCC shows no germline mismatch repair (MMR) gene mutations. We previously detected 'hidden' MMR gene defects in 42% of such families, leaving the remaining 58% 'truly' mutation negative. Here, we characterized 50 colorectal carcinomas and five adenomas arising in HNPCC families; 24 truly MMR gene mutation negative and 31 MMR gene mutation positive. Among 31 tumors from MMR gene mutation positive families, 25 (81%) had active Wnt signaling as indicated by aberrant beta-catenin localization with or without CTNNB1 mutations, compared to only 7/18 tumors from MMR gene mutation negative families (39%; P=0.005). CGH studies revealed stable profiles in 9/16 (56%) of MMR gene mutation negative tumors, which was significantly associated with membranous beta-catenin (P=0.005). Tumors with membranous beta-catenin from the MMR gene mutation negative group also showed low frequency of TP53 mutations compared to those with nuclear beta-catenin. Thus, a majority of the MMR gene mutation negative cases exhibited a novel molecular pattern characterized by the paucity of changes in common pathways to colorectal carcinogenesis. This feature distinguishes the MMR gene mutation negative families from both HNPCC families linked to MMR defects and sporadic cases, suggesting the involvement of novel predisposition genes and pathways in such families.     

Numbers of mutations to different types of colorectal cancer

Background  

The numbers of oncogenic mutations required for transformation are uncertain but may be inferred from how cancer frequencies increase with aging. Cancers requiring more mutations will tend to appear later in life. This type of approach may be confounded by biologic heterogeneity because different cancer subtypes may require different numbers of mutations. For example, a sporadic cancer should require at least one more somatic mutation relative to its hereditary counterpart.     

The impact of a self-help pamphlet on reducing risk drinking among 30- to 49-year-old men in Helsinki, Finland

This study evaluates the impact of a self-help pamphlet designed to support self-control of drinking. It was conducted in Helsinki, Finland, in 2001 and 2002 and focused on men between 30 and 49 years of age. The respondents were randomly selected in an intervention and a control area and compared with each other before and after the intervention using independent samples (N = 4418) The results support previous findings showing that interventions like this serve as a supplement to other prevention and early treatment measures. Although the results were encouraging, there is a need for more in-depth studies in the field.     

Small bowel cyclooxygenase 2 (COX-2) expression in patients with IgA nephropathy

BACKGROUND: Clinical manifestation of IgA nephropathy (IgAN) strikingly occurs after respiratory tract infections. An intestinal inflammation has also been described. We hypothesized that the intestinal inflammation should manifest itself as an increase in inflammatory cells and mucosal cyclooxygenase 2 (COX-2) expression. METHODS: By using immunohistochemistry, we determined the phenotype and quantity of inflammatory cells in duodenal biopsy specimens from 17 IgAN patients. Control material comprised 18 patients undergoing gastroscopy because of dyspepsia. RESULTS: All the biopsy specimens disclosed normal villous architecture. In IgAN, CD3(+) cells and COX-2-positive cells were significantly increased and J chain-producing plasma cells were significantly decreased. CD3(+) cells coexpressed COX-2 protein and COX-2-positive cells also expressed CD45RO antigen. The number of lymphocytes correlated significantly with serum IgA and COX-2-expression with serum IgA and the degree of hematuria. COX-2-positive subepithelial fibroblasts were a conspicuous finding in IgAN. In CD68(+) and CD15(+) cells, a significant increase was seen. Many of these cells also expressed COX-2 protein. CD15(+) positivity correlated significantly with proteinuria in IgAN. CONCLUSION: Our results indicate that small bowel inflammation in IgAN shows itself as an increased number of mucosal inflammatory cells. However, polymeric IgA production is significantly decreased. An increased mucosal COX-2 expression suggests activation of the inflammatory cells and the degree of inflammation significantly correlates with serum IgA and the amount of proteinuria and hematuria. Subepithelial fibroblasts seem also to be involved in the inflammatory reaction.