Łukasz Minarowski

Human cathepsin D.

A literature survey was performed of human cathepsin D gene, cathepsin D biosynthesis, posttranslatory modifications, transport within the cell, substrate specificity and catalytic effect. Methods used to determine the activity and level of this proteinase as well as its role in the biochemistry and pathobiochemistry of cells, tissues and organs were considered.

Thiocyanate concentration in saliva of cystic fibrosis patients.

Thiocyanates (SCN-) are ubiquitous in nature. There are indispensable part of host defense system that act as a substrate for lactoperoxidase (LPO). In our study we present initial data on SCN- concentration in saliva of CF patients in comparison to healthy non-smokers and healthy smokers. 5 ml of saliva was collected from each subject to a sterile tube and thiocyanate concentration was measured in each sample. The results of the measurements are presented on Fig. 1. Mean concentration of SCN- in saliva of CF patients was 0.031 +/- 0.0052 g/l, in healthy non-smokers 0.039 +/- 0.0048 g/l and in healthy smokers 0.048 +/- 0.0161 g/l. The differences between each group were statistically significant. Studies on larger group of patients and probably on different material (BALF or induced sputum) should present interesting data complementing the in vitro studies.

Mild CFTR mutations and genetic predisposition to lactase persistence in cystic fibrosis

Taking into account the reported incidence of hypolactasia in cystic fibrosis (CF) and the possible impact of milk products on nutritional status we aimed to assess the genetic predisposition to adult-type hypolactasia (ATH) and its incidence in CF. Single nucleotide polymorphism upstream of the lactase gene (LCT) was assessed in 289 CF patients. In subject with −13910C/C genotype (C/C) predisposing to ATH, hydrogen-methane breath test (BT) with lactose loading was conducted and clinical symptoms typical for lactose malabsorption were assessed. The percentage of CF patients with C/C was similar to that observed in healthy subjects (HS) (31.5 vs 32.5% ). Eleven out of 52 (24.5%) CF C/C patients had abnormal BT results. The recalculated frequency of lactose malabsorption was similar for the entire CF and HS populations (6.9 vs 7.2%). Similarly as in the control group, few CF patients have identified and linked to lactose consumption clinical symptoms. The frequency of LCT polymorphic variants in CF patients having and not having severe mutations of CFTR gene showed significant differences. The C allele was more frequent in homozygotes of the severe mutations than in patients carrying at least one mild/unknown mutation (P<0.0028) and in patients with at least one mild mutation (P<0.0377). In conclusion, CF patients carrying mild CFTR mutations seem to have lower genetic predisposition to ATH. Lactose malabsorption due to ATH in CF is not more frequent than in the general population. Symptomatic assessment of lactose malabsorption in CF is not reliable.

The activity of N-acetyl-β-d-hexosaminidase A and B and β-glucuronidase in nasal polyps and hypertrophic nasal concha.

UNLABELLED Nasal polyps and hypertrophic lower nasal conchae are common disorders of nasal cavity. The majority of etiopathogenetic theories indicate inflammatory background of polyps and hypertrophic concha. N-acetyl-β-D-hexosaminidase and β-glucuronidase are lysosomal exoglycosidases revealing accelerated activity in inflammatory processes. AIM The aim of the study was to evaluate the catabolism of glycoconjugates in nasal polyps and hypertrophic nasal concha basing on the activity of N-acetyl-β-D-hexosaminidase (HEX) and β-glucuronidase (GLU). MATERIAL AND METHODS Material consisted of nasal polyps taken from 40 patients during polypectomy in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and hypertrophic lower nasal conchae taken from 20 patients during mucotomy. The activity of HEX, HEX A, HEX B and GLU in supernatant of homogenates of nasal polyps and hypertrophic lower nasal concha tissues has been estimated using colorimetric method. RESULTS Statistically significant decrease has been observed in concentration of the activity (per 1mg of tissue) of HEX (p<0.05), HEX B (p<0.001) and specific activity (per 1mg of protein) of HEX B (p<0.001) in nasal polyps tissue in comparison to hypertrophic lower nasal conchae tissue. CONCLUSIONS Decrease in the activity and specific activity concentration of the majority of examined lysosomal exoglycosidases (increasing in inflammations) in comparison to hypertrophic lower nasal conchae suggests electrolytes disorders and questions the inflammatory background of nasal polyps.

Lysosomal exoglycosidases in nasal polyps.

INTRODUCTION Nasal polyps are smooth outgrowths assuming a shape of grapes, formed from the nasal mucosa, limiting air flow by projecting into a lumen of a nasal cavity. Up to now the surgical resection is the best method of their treatment, but etiology and pathogenesis of the nasal polyps is not yet fully established. AIM OF THE STUDY The aim of the study was the assessment of the selected lysosomal exoglycosidases activity in the nasal polyps. In this study the activity of β-galactosidase, α-mannosidase and α-fucosidase was determined in the tissue of the nasal polyps obtained from 40 patients (10F, 30M) and control tissues derived from mucosa of lower nasal conchas obtained during mucotomy from 20 patients (10F, 10M). RESULTS We observed significant lower values of GAL, FUC and tendency to decrease of MAN and GLU concentration in nasal polyps (P) in comparison to control healthy nasal mucosa (C). In nasal polyp tissue (P) no differences of GAL, MAN and FUC specific activity in comparison to control mucosa (C) were found. CONCLUSIONS Our research supports bioelectrical theory of the nasal polyps pathogenesis and directs attention at research on glycoconjugates and glycosidases of the nasal mucosa extracellular matrix.

Role of cathepsin A and cathepsin C in the regulation of glycosidase activity.

Increased tissue activity of cathepsin A and cathepsin C can be observed in many pathological conditions. It is associated with an enhanced degradation of glycosaminoglycans, proteoglycans, and glycoproteins, and results in their decreased tissue content. Cathepsin C releases the glycosidases from complexes formed with cathepsin A, and reinstates their activity. In this review a current state of knowledge is presented concerning the regulation of selected glycosidases activity by cathepsin A (EC 3.4.16.1) and C (EC 3.4.14.1).

N-acetyl-β-hexosaminidase in chronic tonsillitis and tonsillar hypertrophy.

BACKGROUND The concentration and specific activity of N-acetyl-β-hexosaminidase (HEX) in palatine tonsils with chronic tonsillitis and tonsillar hypertrophy give insight in tonsillar tissue remodeling and constitute a potential marker for diagnosis and treatment of chronic tonsillitis and tonsillar hypertrophy. AIM Determining the concentration and specific activity of N-acetyl-β-hexosaminidase in palatine tonsils with hypertrophy and chronic tonsillitis. METHODS HEX activity was analyzed by the method of Marciniak et al. with p-nitrophenyl N-acetyl-β-glucosaminepyranoside as a substrate. RESULTS The concentration and specific activity of HEX in palatine tonsils in patients with tonsillar hypertrophy and chronic tonsillitis both in childhood and adulthood significantly increase in comparison to healthy individuals. CONCLUSIONS Our data demonstrate the presence of HEX in palatine tonsils and indicate on significant increase of its concentration and specific activity. Based on content and specific HEX activity we suggest that tonsils with hypertrophy and chronic tonsillitis should be treated as identical unit irrespectively of age.

Excessive daytime sleepiness and risk for obstructive sleep apnea in the public transport drivers

BACKGROUND Obstructive sleep apnea (OSA) is a set of symptoms related to the increased upper airways resistance during sleep (due to pharyngeal walls collapse) leading to intermittent airflow obstruction in the lungs. One of the most severe OSA symptoms is excessive daytime sleepiness. Sustained daytime sleepiness may impair cognitive functions and thus influence the everyday functioning of affected person. MATERIAL AND METHODS The aim of the study was to prospectively assess excessive daytime sleepiness and the risk for OSA in municipal bus drivers. The study was performed in a group of 103 men. The anonymous survey comprised Epworth Sleepiness Scale (ESS) for daytime sleepiness assessment and STOP-Bang Questionnaire (SBQ) for OSA risk assessment. RESULTS In 43 (42%) respondents OSA risk was assessed as low, while moderate and high risk was observed in 55 (53%) and 5 (5%) drivers, respectively. Severe daytime sleepiness correlated positively with ESS results (r = 0.32; p < 0.05). In drivers with high OSA risk revealed in SBQ no correlation with high ESS was observed. CONCLUSIONS In drivers with moderate and high OSA risk a sleep medicine specialist consultation with a consecutive diagnostic procedures is necessary. STOP-Bang Questionnaire and ESS are the fast tools to identify patients at increased risk for OSA.