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Biomedical subjects

P Capek

Publications and source records attributed to P Capek.

At least 19 recordsLinked to original sources

Hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy is a multigenetic cardiac disease with autosomal dominant pattern of inheritance and incomplete penetrance, with the exclusion of those cases caused by mutations in the mitochondrial genome. The disease is usually caused by mutations in several sarcomeric contractile protein genes. Mutations have been found in four genes that encode components of the thick filament: beta myosin heavy chain (5), essential myosin light chains (6), regulatory myosin light chains (6), and cardiac myosin binding protein -C (7), (8); in five genes that encode thin filament proteins: cardiac actin (9), cardiac troponin T (10), cardiac troponin C (11), cardiac troponin I (12), and alpha-tropomyosin (10); and in the sarcomeric cytoskeletal protein titin (13). In addition to mutations in contractile sarcomeric proteins, mutations in other genes encoding for non-sarcomeric proteins also have been identified in patients with-non pure form of hypertrophic cardiomyopathy. As a complex cardiac disease, hypertrophic cardiomyopathy has unique pathophysiological characteristics and a various morphological, functional, and clinical features.

Cardiomyopathy, Hypertrophic↗

Hypertrophic cardiomyopathy--molecular genetic analysis of exons 9 and 11 of the TNNT2 gene in Czech patients.

OBJECTIVES: Our research is a pilot study that specializes in the molecular genetic investigation of the TNNT2 gene in Czech patients with HCM/FHC disease. This study was initiated with exons 9 and 11 of TNNT2 because of their crucial role in the binding ability of cardiac troponin T to alpha-tropomyosin, and continued with analyses in other regions of the gene. METHODS: Hundred and eighty-one Czech probands with HCM/FHC were enrolled in this study. The study group consisted of 24 families with FHC and probands without FHC history but with HCM diagnosis. The clinical diagnosis was based on echocardiography. DNA was isolated from peripheral blood lymphocytes and subsequently analyzed by the polymerase chain reaction (PCR), followed by DNA sequencing analyses, which were cross-sequenced. RESULTS: The DeltaGlu160 mutation was observed in a sequence of the TNNT2 gene in a patient with the severe form of hypertrophic cardiomyopathy. No sequence alteration was found in exons 9 and 11 of the TNNT2 gene found in the rest of the DNA samples. CONCLUSION: The DeltaGlu160 mutation was observed in patients with severe forms of hypertrophic cardiomyopathy. This region is responsible for binding troponin T to alpha-tropomyosin. This mutation may lead to functional and structural effects on the troponin T protein. Mutations in this region are reported relatively rarely and therefore it was unique to observe the DeltaGlu160 mutation in our study.

Base Sequence↗

Degradation of wheat straw by Fibrobacter succinogenes S85: a liquid- and solid-state nuclear magnetic resonance study.

Wheat straw degradation by Fibrobacter succinogenes was monitored by nuclear magnetic resonance (NMR) spectroscopy and chemolytic methods to investigate the activity of an entire fibrolytic system on an intact complex substrate. In situ solid-state NMR with 13C cross-polarization magic angle spinning was used to monitor the modification of the composition and structure of lignocellulosic fibers (of 13C-enriched wheat straw) during the growth of bacteria on this substrate. There was no preferential degradation either of amorphous regions of cellulose versus crystalline regions or of cellulose versus hemicelluloses in wheat straw. This suggests either a simultaneous degradation of the amorphous and crystalline parts of cellulose and of cellulose and hemicelluloses by the enzymes or degradation at the surface at a molecular scale that cannot be detected by NMR. Liquid-state two-dimensional NMR experiments and chemolytic methods were used to analyze in detail the various sugars released into the culture medium. An integration of NMR signals enabled the quantification of oligosaccharides produced from wheat straw at various times of culture and showed the sequential activities of some of the fibrolytic enzymes of F. succinogenes S85 on wheat straw. In particular, acetylxylan esterase appeared to be more active than arabinofuranosidase, which was more active than alpha-glucuronidase. Finally, cellodextrins did not accumulate to a great extent in the culture medium.

Animals↗

Characterization of immunomodulatory polysaccharides from Salvia officinalis L.

Crude polysaccharide fractions, rich mainly in arabinogalactans (A), pectin (B) and glucuronoxylan-related polymers (D), have been obtained from aerial parts of sage (Salvia officinalis L.) by sequential extraction with various reagents. Arabinogalactans displayed on HPLC a dominance of lower molecular-mass polymers (MW < 10,000), while pectin and glucuronoxylan-related polysaccharides showed predominance of polymers with MW > 50,000. Individual polysaccharide fractions were examined for their immunomodulatory activity in the in vitro comitogenic thymocyte test. The polysaccharide fractions tested possessed the capacity to induce rat thymocyte proliferation in the order D>B>A. Besides, fraction D possessed a significant comitogenic effect, and the SIcomit/SImit ratio 3-4 indicates potential adjuvant properties of this glucuronoxylan-rich material.

Adjuvants, Immunologic↗

Galactoglucomannan from the secondary cell wall of Picea abies L. Karst.

The fine structural features of alkali-extracted galactoglucomannan composed of D-galactose, D-glucose and D-mannose in a 1:8:33 mole proportion from the secondary cell walls of Picea abies L. Karst have been determined. Compositional and methylation analyses of the polymer, partial acid hydrolysis, as well as 1H and 13C NMR measurements of the polymer and products of partial acid hydrolysis confirmed a beta-(1-->4)-linked backbone of galactoglucomannan containing the segments of mannosyl residues (Man2, Man3, Man4, etc.) interrupted with the segments having both mannose and glucose residues, as well as the segments in which D-Glcp units can be adjacent to each other (Glc2). Further, the low content of branching points (approximately 3%) at the positions of 0-6, 0-3 and 0-2 of mannosyl and 0-6 and 0-3 of glucosyl residues, but preferably of mannosyl ones, indicates the presence of short side-chains terminated at position 0-6 predominantly by D-galactose units as single stubs.

Carbohydrate Sequence↗

Major histocompatibility complex class II antigen expression in rejecting cardiac allografts: detection using in vivo imaging with radiolabeled monoclonal antibody.

BACKGROUND: Increased expression of major histocompatibility complex class II (MHC-II) antigen occurs during cardiac allograft rejection. We tested the hypotheses that (1) radiolabeled antibody to MHC-II antigen allows detection of cardiac allograft rejection using nuclear imaging techniques and (2) uptake of radiolabeled antibody to MHC-II antigen correlates with severity of rejection. METHODS AND RESULTS: Thirteen beagles with cervical cardiac allografts were studied for 64+/-23 days by use of myocardial biopsy and in vivo imaging. Uptake of radiolabeled (131I [n=2], 123I [n=1], or 111In [n=10]) antibody to MHC-II increased over baseline in 7 animals that developed histological evidence of progressively worsening allograft rejection (group A), from 72.2+/-46.1 to 176.8+/-102.0 counts/pixel/mCi (P<.009). In 4 beagles without progressively worsening allograft rejection (group B), uptake was unchanged during follow-up (74.4+/-43.8 and 60.2+/-37.4 counts/pixel/mCi; P=NS). In animals studied with 111In-labeled antibody, uptake increased from 102.9+/-23.1 at baseline to 233.2+/-82.7 counts/pixel/mCi at follow-up in group A animals (P=.036), with no significant change in group B (91.1+/-34.9 and 75.9+/-24.9 counts/pixel/mCi; P=NS). Uptake of 111In-labeled antibody was 107.5+/-35.7, 135.9+/-70.8, and 307.8+/-90.1 counts/pixel/mCi in biopsy samples showing evidence of mild, moderate, and severe rejection, respectively (P=.001). Biopsy samples showing mild, moderate, and intense MHC-II expression antibody uptake had uptakes of 92.6+/-36.3, 158.5+/-54.7, and 307.8+/-90.1 counts/pixel/mCi, respectively (P=.00004). CONCLUSIONS: Radiolabeled monoclonal antibodies to MHC-II antigen can detect cardiac allograft rejection in this large mammal model of cardiac allograft transplantation, and this technique may have a potential role in the detection of rejection in patients after cardiac transplantation.

Animals↗

Improved left ventricular function after chronic left ventricular unloading.

BACKGROUND: This study assessed the effect of prolonged left ventricular unloading on native ventricular function. METHODS: We reviewed data from 31 patients (30 men, 1 woman) supported more than 30 days (mean, 137 days; range, 31 to 505 days) with the HeartMate left ventricular assist system. The patients' mean age was 46 years (range, 22 to 64 years); 17 had idiopathic and 14 had ischemic cardiomyopathy. Data (anatomic, physiologic, hemodynamic, histologic, and biochemical) were collected at the time of HeartMate implantation, during support with the device temporarily off, and at the time of device explantation. RESULTS: Routine chest roentgenogram showed improvement in cardiothoracic ratio (0.62 +/- 0.04 to 0.55 +/- 0.03; p < 0.0001). Echocardiography performed with the pump off showed a significant decrease in left ventricular end-diastolic dimension (6.81 +/- 0.87 cm to 5.39 +/- 1.08 cm; p < 0.0005) and a significant improvement in ejection fraction (0.11 +/- 0.05 to 0.22 +/- 0.17; p < 0.02). Cardiac index increased (1.96 +/- 0.52 L.min-1.m-2 to 2.93 +/- 0.73 L.min-1.m-2; p < 0.0001), mean aortic pressure increased (71.40 +/- 10.63 mm Hg to 76.33 +/- 16.84 mm Hg; p = 0.48), pulmonary capillary wedge pressure decreased (24.18 +/- 6.27 mm Hg to 14.48 +/- 3.01 mm Hg; p < 0.0001), and pulmonary vascular resistance decreased (3.34 +/- 2.00 Wood units to 2.51 +/- 0.88 Wood units; p < 0.05). Comparisons of tissue samples taken at the time of implantation and at the time of transplantation showed a marked reduction in myocytolysis. Calcium uptake, calcium-binding rates, and lipid levels normalized in patients studied. Plasma norepinephrine levels decreased to near normal levels. CONCLUSION: Prospective studies are now indicated to determine whether device removal without transplantation may be beneficial in selected patients.

Adult↗

Enzymatic degradation of cell walls of apples and characterization of solubilized products.

Partially depectinated apple cell walls were digested by pectin lyase or endoglucanase or a combination. By combining these commercial enzymes, a higher yield of 22.2% of carbohydrate material was obtained compared with only 13.9% and 5.7%, respectively, when using them singly. Only small amounts of carbohydrates were extracted by buffer (0.8%). The solubilized extracts were fractionated using a combination of ion-exchange chromatography and gel filtration. The individual subfractions were analysed for neutral sugar and uronic acid content. The results indicated the existence of a synergistic effect between pectin lyase and endoglucanase based on the percentage of material extracted.

Carbohydrates↗

Cardiac sarcoidosis. An unusual form of acute congestive cardiomyopathy.

We report the case of a previously healthy 45-year-old white man in whom sustained ventricular tachycardia and severe myocardial dysfunction were the only signs of cardiac sarcoidosis. Diagnosis was confirmed by endomyocardial biopsy, and the patient responded well to treatment with amiodarone and prednisone.

Biopsy↗

Methyl-alpha-D-mannopyranoside, mannooligosaccharides and yeast mannans inhibit development of rat adjuvant arthritis.

Methyl-alpha-D-mannopyranoside, mannooligosaccharides obtained by acetolysis of yeast mannan, and pure mannans isolated from the cell walls of pathogenic (Candida albicans) and nonpathogenic (Saccharomyces cerevisiae) yeasts were used for treatment of rat adjuvant arthritis. The arthritis was induced by the application of Freund's complete adjuvant into the tail region of rats. The mannose substances were injected into the arthritic rats intraperitonealy at different time intervals. Levels of serum albumin, changes in hindpaws swelling and radiographs were measured in infected rats as variables of the inflammation and destructive arthritic changes. While mannan from C. albicans inhibited both the inflammation and destructive arthritic changes, mannan from S. cerevisiae showed less effect. However, acetolysate of S. cerevisiae mannan as well as simple methyl-alpha-D-mannopyranoside inhibited both inflammation and destructive arthritic changes to a similar degree as mannan isolated from C. albicans. The effect, which is not dose dependent indicates its possible immunoregulatory mechanism. This is the first time a therapeutic effect of simple carbohydrates on rat adjuvant arthritis has been described.

Animals↗

Ligand recognition by purified human mannose receptor.

In this work we examine the carbohydrate binding properties of human placental mannose receptor (HMR) using a rapid and sensitive enzyme-linked immunosorbent microplate assay. The assay is based on the inhibition of binding of highly purified receptor to yeast mannan-coated 96-well plates. The specificity of ligand binding was inferred from the potency of different saccharides in blocking HMR binding to the mannan-coated wells. The relative inhibitory potency of monosaccharides was L-Fuc greater than D-Man greater than D-Glc greater than D-GlcNAc greater than Man-6-P much greater than D-Gal much greater than L-Rha much greater than GalNAc. The inhibitory potency of mannose increased by two orders of magnitude when linear oligomers were used. Oligomers containing alpha-1-3- and alpha-1-6-linked mannose residues were more inhibitory than those containing alpha-1-2- and alpha-1-4-linked mannoses. Linear or branched oligomannosides larger than three units did not have a significant influence on their inhibitory potency; rather, potency was found to decrease in comparison with oligomannosides with three units. Compared to linear oligomers, inhibition of binding was the best using branched mannose oligosaccharides, alpha-D-Man-bovine serum albumin conjugates, or mannan. A model is discussed in which branched ligand is bound to spatially distinct sites on the HMR.

Binding, Competitive↗

[Antitussive action of extracts and polysaccharides of marsh mallow (Althea officinalis L., var. robusta)].

The complex extract and the polysaccharide isolated from the roots of marsh mallow were tested for antitussive activity in unanaesthetized cats of both sexes. Cough was elicited by mechanical stimulation of laryngopharyngeal and tracheobronchial mucous area of the respiratory system with a Nylon fibre (diameter 0.35 mm). Cough was evaluated on the basis of the changes in lateral tracheal pressure. The polysaccharide and the complex extract were administered p.o. in a dose of 50 and 100 mg/kg b.w., respectively. The efficiency of the mentioned compounds was compared with the cough-suppressing effect of drugs belonging to the non-narcotic antitussics. The results of the experiments showed that administration of the polysaccharide led to a statistically significant decrease of the number of cough efforts both from laryngopharyngeal and tracheobronchial areas of the the respiratory system. The polysaccharide in a dose of 50 mg/kg b.w. was as effective in inhibition of the cough reflex as Sirupus Althaeae in a dose of 1000 mg/kg b.w. and more effective than prenoxdiazine in a dose of 30 mg/kg b.w. However, the cough-suppressing effect of the polysaccharide was lower than that of dropropizine. The extract was less effective than the polysaccharide.

Animals↗

Base-catalyzed degradation of permethylated 3-O-glycosyl- glycopyranosid-2-uloses.

In a modification of the Svensson degradation, otherwise permethylated glycopyranosid-2-uloses bearing 4-O-glycosyl substituents are formed by the Swern oxidation. Base-catalyzed elimination on treatment with triethylamine then gives 4-deoxy-3-O-methylglyc-3-enopyranosid-2-ulose-terminat ed oligosaccharides with liberation of glycosyl substituents as reducing sugars but without further degradation. Mild acid hydrolysis results in removal of the unsaturated sugar residues so that the overall depolymerization occurs with net loss only of the initially oxidized sugar residue.

Carbohydrate Sequence↗

A novel L-fuco-4-O-methyl-D-glucurono-D-xylan from Hyptis suaveolens.

The acidic polysaccharide from the seed-coat mucilage of Hyptis suaveolens is a highly branched L-fuco-4-O-methyl-D-glucurono-D-xylan for which a structure is proposed having a 4-linked beta-D-xylan backbone carrying side chains of single 4-O-methyl-alpha-D-glucuronic acid residues at O-2 and 2-O-L-fucopyranosyl-D-xylopyranose units at O-3. The structural analysis involves base-catalyzed beta-elimination of uronic acid residues from the methylated glycan followed by degradation using a modified Svensson oxidation-elimination sequence.

Carbohydrate Sequence↗

Left ventricular papillary fibroelastoma. An unusual cause of cerebral emboli.

We describe the case of a 63-year-old woman with a cardioembolic neurologic deficit secondary to papillary fibroelastoma, a rare intracardiac tumor. Diagnosis was made by use of 2-dimensional and transesophageal echocardiography. The tumor was surgically resected, and the patient had an uneventful recovery. In this report, we discuss the embolic potential of papillary fibroelastoma and the appropriate diagnostic and surgical approaches for patients with this rare disorder.

Journal Article↗

[Techniques of endoscopic treatment of malignant colorectal adenomas with respect to the subsequent prognosis of the patients].

Since 1981 we detected in 45 patients (28 men, 17 women) 31 adenomas with severe dysplasia (ATD; formerly intramucous carcinoma) and 22 invasive carcinomas in the adenoma (IK penetrating beneath the muscularis mucosae). 95% of all findings were in the left colon before the lienal flexure. Patients with ATD were subjected only to endoscopic operation; of 22 of the subjects with IK 15 were recommended for surgery, and endoscopic treatment alone was provided to seven patients. Forty subjects were followed up on a long-term basis (on average for 34 months). Of 23 patients with ATD one female patient died from ischaemic heart disease, the remainder survive without signs of colorectal carcinoma. Of 17 subjects with IK followed up on a long-term basis five died (all after surgery as a result of generalization of the disease). All 7 patients with IK who had only endoscopic treatment survive without signs of relapse of the disease. In patients with ATD the authors consider EP as the definite therapeutic method, if it is feasible from the technical aspect. Patients with ATD and IK who were subjected to EP are checked after 6 weeks. A total coloscopic check-up is made subsequently in subjects with IK during the first year twice a year and in later years once a year, in subjects with ATD after annual intervals for a period of 5-6 years.

Adenoma↗

Femoropopliteal angioplasty. Factors influencing long-term success.

Prospective data was recorded on 217 percutaneous transluminal angioplasty (PTA) procedures performed in the superficial femoral and popliteal arteries over an 8-year period. After the initial procedure, patients were followed with serial noninvasive studies and, in 71 patients, repeat angiography. The mean follow-up period was 7 years (range, 2-11 years). Standard life-table survival analysis was used to assess the factors potentially affecting long-term outcome. Excluding an initial technical failure rate of 10%, overall patencies at 1, 3, and 5 years were 81%, 61%, and 58%, respectively. After the first year, the prognosis (i.e., failure rate) appears to be linear over the long term (i.e., up to 10 years). Factors negatively influencing long-term patency include the presence of diabetes mellitus, diffuse atherosclerotic cardiovascular disease, or threatened limb loss. Technical factors correlated with failure include lesion length, moderate eccentricity, and a poor post-PTA appearance.

Angioplasty, Balloon↗