Biomedical subjects

J Grzybowski

Publications and source records attributed to J Grzybowski.

At least 37 records · Page 2Linked to original sources

PubMed1997

[Treatment using Polish collagen biomaterials].

The article presents the review of all published and not published results of clinical investigations of new polish collagen biomaterials that have been registered in Poland recently. Two main medical applications of the biomaterials--used as hemostatic tampons and/or as biological dressings for wound care have been described here. The collagen sponges proved to be useful in chronic wound care and for hemostasis of bleeding wounds. The collagen membranes are effective in extensive superficial wounds care (burns, skin donor places or wounds after dermabrasion).

Biocompatible Materials↗

PubMed1996

Increased frequency of organ-specific cardiac antibodies in healthy relatives of patients with dilated cardiomyopathy: evidence for autoimmunity in Polish families.

BACKGROUND AND HYPOTHESIS: Autoantibodies represent markers of autoimmune involvement and are found with increased frequency in patients and their symptom-free relatives at risk compared with normal controls. Cardiac-specific autoantibodies, detected by immunofluorescence, were found in 20% of symptom-free relative of patients with dilated cardiomyopathy (DCM) from England and Italy. The role of autoimmunity may vary in DCM patients from Poland due to ethnic differences in genetic susceptibility to autoimmune disease. METHODS: We assessed the frequency of the organ-specific cardiac autoantibodies in 162 symptom-free relatives of DCM patients [85 male, mean (SD) age 27 (18) years] and 80 control subjects from Poland. Familial DCM (> 1 affected member) was present in 4 families, nonfamilial DCM in the remaining 24 pedigrees. We performed antibody screening and noninvasive cardiological assessment in the whole group. RESULTS: The frequency of cardiac-specific autoantibodies was higher among patients with documented DCM (probands and relatives) (50%) and their symptom-free relatives (38%) than in unrelated normal subjects (10%; p = 0.0001). In 24 (86%) of the pedigrees studied, autoantibodies were found in the proband and/or in at least one family member and tended to be more common in familial than in nonfamilial DCM (50 vs. 35%, p = NS). Echocardiographic indices of left ventricular size and function were similar in relatives with and without detectable antibodies. CONCLUSIONS: The presence of cardiac-specific autoantibodies in symptom-free relatives of DCM patients provides evidence for autoimmunity in the majority (86%) of our pedigrees, including both familial and nonfamilial forms of DCM.

Adolescent↗

PubMed1996

Anti-pseudomonal activity of collagen sponge with liposomal polymyxin B.

An antibiotic delivery system has been developed using collagen sponge with liposome-encapsulated polymyxin B. Superficial, non-lethal infection was produced in mice by injecting Pseudomonas aeruginosa into the skin windows. Wounds were dressed with collagen sponge containing liposomal polymyxin B or containing empty liposomes (with PBS) as a control. Single dose of topically applied collagen sponge with encapsulated polymyxin B decreased bacterial cell number as compared to the control. Finally, after 8 days of experiment, the number of bacterial colonies dropped below 10(4) per biopsy. Presented polymyxin B delivery system offers potential clinical advantages.

Animals↗

PubMed1996

The influence of Pseudomonas aeruginosa on liposomes.

The interaction of liposomes loaded with Ponceau red (used as a marker) with Pseudomonas aeruginosa cells was observed and it resulted in marker leakage. The marker leakage from liposomes was low in physiological fluids. The interaction was independent of secreted phospholipase C level and the serotype of the tested strain. Six of 37 examined isolates did not cause any release of the marker from the liposomes. Marker release of over 50% of total encapsulated material was observed only for ten of the strains tested.

Anti-Bacterial Agents↗

PubMed1996

A simple in vitro model to test the efficacy of antimicrobial agents released from dressings.

A new model for in vitro evaluation of an activity of antibacterial agents released from delivery systems containing antibiotics or antiseptics was developed. The model was composed of two layers of agar gel of two different concentrations in PBS. In the upper gel, the wells were cut and filled with polyurethane sponges saturated with bacterial broth culture. The sponges were then covered with tested dressings containing antibacterial agent. The model was tested by using two bacterial strains, Pseudomonas aeruginosa or Staphylococcus aureus and experimental collagen dressing with doxycyclin, amikacin, or with silver sulfadiazine. The number of colony-forming units (CFU) in the polyurethane sponges was significantly lower under the dressings with antibacterial agents as compared to the control (the same dressing without antimicrobials) during 3 days of observation. The new in vitro model can be recommended for examination of different antibacterial delivery systems instead of experimentally infected wounds in laboratory animals or instead of the other in vitro models.

Agar↗

PubMed1996

Determinants of prognosis in nonischemic dilated cardiomyopathy.

BACKGROUND: Dilated cardiomyopathy, a heart muscle disease of unknown cause, is characterized by high mortality and is a major cause of cardiac transplantation. It has become, therefore, increasingly important to identify patients at higher risk. The aim of this study was to assess which of the data obtained at the time of diagnosis are the best predictors of survival. METHODS AND RESULTS: One hundred forty-four patients with dilated cardiomyopathy (118 men; mean age, 39 years) were assessed clinically, noninvasively, and hemodynamically. The effect of variables derived from the evaluation on outcome (death or heart transplantation) was examined. During a mean follow-up time of 4.1 years, 68 patients (47%) died and 9 (6%) underwent heart transplantation. The 1-, 2-, and 5-year transplant-free survival rate was 79, 69, and 44%, respectively. Cox multivariate regression analysis identified three variables as independent predictors of outcome: (1) pulmonary artery systolic pressure, P = .0001; (2) left ventricular ejection fraction, P = .0013; and (3) left ventricular end-diastolic dimension, P = .007. The prognostic index was constructed from regression coefficients and parameters significant in the Cox model. The minimal prognostic index in the study group was 1.4 and the maximal was 6.0 with a corresponding 1-year survival of 98 and 18%, respectively. The validity of the prognostic index was tested in the consecutive group of 81 patients, who were followed for a mean 2.3 years. The prognostic index of the poor outcome group differed significantly from that in survivors (3.7 vs 2.9, respectively, P < .01). The sensitivity and specificity of model predictions were 68 and 52%, respectively. CONCLUSIONS: The severity of pulmonary hypertension and left ventricular dysfunction provides an independent insight into the prognosis of patients with dilated cardiomyopathy. The prognostic index is useful when assessing prognosis and may be helpful in the timing of heart transplantation.

Adult↗

PubMed1996

[Collagen membranes of increased absorption as carriers of antiseptics].

Collagen membranes of increased absorption were prepared by incubation in the acidic solutions and lyophilization. The organic acids and hydrochloric acid solutions were used for this purpose. The membranes incubated in 2% citric acid possessed of highest absorption. Microdressings containing povidone-iodine or chlorhexidine glycerin solution were prepared using the collagen membranes of increased absorption. The microdressings were packed into envelopes made of laminated aluminium foil; they were stabile for eight weeks concerning their antibacterial activity. After implantation beneath mouse skin the dressings did not cause inflammation. Such dressings may be useful in a treatment of ulcers, superficial burns and chronic granulated wounds.

Absorption↗

PubMed1995

Synthetic oligonucleotide cocktails as probes for detection of human parvovirus B19.

A cocktail of 10 oligonucleotides selected at intervals along the length of the genome of human parvovirus B19 was labelled enzymically with digoxigenin and chemically with either digoxigenin (DIG) or dinitrophenyl (DNP). Chemical labelling was easier and more practical for the production of large quantities of probe. Pools labelled with either digoxigenin or DNP could detect 10 fg of B19 DNA in a dot blot reaction using an alkaline phosphatase antibody conjugate and colorimetric detection. Formalin fixed tissue from 11 consecutive cases of fetal hydrops were examined by in situ hybridisation (ISH). Both probe cocktails detected human parvovirus B19 DNA in 3 cases, with positive cells in all tissues examined and with equal sensitivity. The DNP pool is significantly cheaper and simpler to produce and could provide an inexpensive reagent suitable for diagnostic detection of viral nucleic acid in histopathological material.

Base Sequence↗

PubMed1995

Left ventricular enlargement is common in relatives of patients with dilated cardiomyopathy.

Idiopathic dilated cardiomyopathy is characterized by dilation and impaired contractility of one or both ventricles. Long-term prognosis is poor. Early diagnosis has the potential for substantial reduction of morbidity and mortality. Recent studies, based on echocardiographic assessment of relatives of the patients have shown that familial dilated cardiomyopathy is relatively common. The authors studied 215 relatives (mean age, 27 years; 111 male) of 38 index patients with idiopathic dilated cardiomyopathy by clinical examination, electrocardiography, and two-dimensional, M-mode and Doppler echocardiography. Seven relatives (3%) from six families were shown to have dilated cardiomyopathy. Thus, 6 of the 38 index patients (16%) had familial disease. Furthermore, left ventricular enlargement either during diastole or systole was found in 66 of 174 healthy relatives (38%). This is significantly more frequent than in our normal control population of 100 unrelated subjects studied in the same way (18%; P < .0001). These 66 relatives with left ventricular enlargement belonged to 27 of the 38 examined families (71%). Dilated cardiomyopathy was found to be familial in 16% of patients. Of the relatives examined, 41% had left ventricular abnormalities. These findings provide further evidence for a genetic background of dilated cardiomyopathy. Relatives with left ventricular enlargement may have an early stage and/or latent form of the disease.

Adult↗

PubMed1995

Organ-specific cardiac autoantibodies in dilated cardiomyopathy. Frequency and clinical correlates in Polish patients.

Organ- and disease-specific cardiac autoantibodies are found in a third of dilated cardiomyopathy patients from the U.K. and Italy and represent markers of autoimmune involvement. The role of autoimmunity may vary in dilated cardiomyopathy patients from different countries due to differences in genetic susceptibility to autoimmune diseases. The aim of this study was to assess the frequency of organ-specific cardiac autoantibodies detected by immunofluorescence in a consecutive series of patients with dilated cardiomyopathy and in disease and normal control subjects from Poland. The study groups included 79 patients with idiopathic (WHO criteria) dilated cardiomyopathy, 55 patients with other cardiac disease and 60 normal subjects. Cardiac antibody tests were performed by indirect immunofluorescence on human heart; skeletal muscle was used to identify cross-reacting antibodies. The frequency of organ-specific cardiac autoantibodies was higher in patients with dilated cardiomyopathy (21/79, 27%) than in controls with other cardiac disease (1/55, 2% P < 0.001) or in normal subjects (7/60, 12% P < 0.02). Conversely, cross-reactive antibodies were detected in similar proportions in patients with dilated cardiomyopathy (5/79, 6%), disease controls (7/55, 13%) and normal subjects (6/60, 10%, P = ns). The organ-specific antibody was more common in patients with dilated cardiomyopathy with insidious onset of disease (17/34, 50%) compared to those who did not exhibit this feature (4/45, 9%, P < 0.0001). Organ- and disease-specific cardiac autoantibodies were found in 27% of Polish patients with dilated cardiomyopathy at diagnosis; this is evidence for autoimmune involvement in a subset of patients from our country, as seen in a previously reported series of Western European origin. The association of antibody status with insidious onset of symptoms is in keeping with the long latency period observed in other autoimmune disorders.

Adult↗

PubMed1995

Effects of free and liposome-encapsulated antibiotics on adherence of Pseudomonas aeruginosa to collagen type I.

The adherence of 27 clinical Pseudomonas aeruginosa strains to collagen type I was investigated by using a solid-phase assay. The influence of free antibiotics (amikacin, gentamicin, piperacillin, bacitracin, and polymyxin B) and liposome-entrapped antibiotics (amikacin and polymyxin B) on bacterial attachment to collagen type I was examined. The greatest inhibitory effect was shown for free and liposomal amikacin, which decreased the attachment of 74 and 100% of tested strains, respectively. The mean percent attachment (+/- standard deviation) in the presence of free amikacin was 65.7% (+/- 12.0%) as measured by solid-phase assay. In the presence of liposomal amikacin, the attachment ranged from 17.3% (+/- 6.0%) to 42.1% (+/- 9.4%), depending on the antibiotic solvent. In contrast, polymyxin B, even at a subinhibitory concentration, enhanced attachment of all P. aeruginosa isolates to collagen. Liposomal polymyxin B displayed a protective effect only when the encapsulated drug was of a low concentration. Application of liposome-encapsulated amikacin may be advantageous in injured tissues in which extracellular matrix structures become exposed.

Amikacin↗

PubMed1995

Mouse model of infected wound.

Local Pseudomonas aeruginosa infection of experimental wound in mice was performed. Suspension of living bacteria was injected beneath skin muscle after skin window had been made on the back of animals. On day 1, 2, 3 and 8 mice were sacrificed, biopsies were taken, number of colony forming units in muscle specimens was estimated and histological examination of skin muscle flaps was performed. The number of bacteria dropped from the very beginning of experiment to the eighth day after infection, still remaining higher than critical value of clinical infection (10(5) CFU per 1 g). Histologically, healing processes beneath skin started from the third day and on the eight day the wounds were practically healed. Developed model of infected wound may be useful to study the antibacterial agents' effectiveness.

Animals↗

PubMed1995

Clinical application of new bovine collagen membranes as a partial-thickness burn wound dressing.

New bovine collagen membranes were applied for covering of partial-thickness burn wounds to compare with porcine skin used as biological dressing. Forty four of investigated patients had superficial (2a degree), and forty four of them had deep (2b degree) partial thickness burn wounds. When nonperforated collagen membranes or porcine skin were used for dressing of superficial (2a degree) burn wounds, time of healing was established as 11 +/- 3.4 (mean + or - sd) and 12+/- 4.9 days, respectively (n=12). For perforated version of the dressings the time of healing was 9 +/- 3.5 and 10 +/- 3.2, respectively (n=10). The differences were nonsignificant in both cases. When nonperforated collagen membranes or porcine skin were used for treatment of deep (2b degree) burn wounds, the time of healing was established as 29 + or - 6.1 and 30 +/- 5.4 days, respectively ( n=10). The differences were nonsignificant as well. We can conclude from our study that new collagen membranes can be considered as biological dressings and can be recommended for partial-thickness burn wound care. Perforated version of the collagen membranes was better than nonperforated.

Adolescent↗

PubMed1995

[A comparative examination of the hemostatic properties of xenogenic collagenic biomaterials].

The results of haemostatic properties examination of bovine collagen membranes and sponges manufactured in Poland in comparison to Spongostan are presented. In the first step of investigation the experiments were performed using punctured mouse livers. The second step comprised clinical trials in seven patients hospitalised in the Department of Plastic Surgery. The estimated parameter was the time of parenchymal bleeding from punctured livers of from donor places after cutting of the skin for split thickness grafts. The application of tested collagenic membranes or sponges caused effective decreasing of bleeding time. They are potent agents in the cases of abundant capillary bleeding of parenchymal organs and cutaneous tissues. The efficacy of hemostasis initiated by collagen membranes was the same as for Spongostan. The highest haemostatic potency possessed collagenic sponge.

Adult↗

PubMed1994

1,25-Dihydroxyvitamin D3 increases collagen production in dermal fibroblasts.

The effect of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on proliferation and collagen type I and type III production in cultured human fibroblasts was examined. Previous studies have identified receptors for the vitamin in human dermal fibroblasts, and have suggested the skin to be a target tissue. While many studies examining keratinocyte modulation by 1,25-(OH)2D3 have been undertaken, very few have been performed on dermal fibroblasts. Neonatal foreskin fibroblast cultures were examined for cell number, extracellular collagen accumulation, and collagen mRNA levels, after 5 days exposure to 1,25-(OH)2D3 at a concentration of 10(-7) M. The vitamin significantly suppressed (P < 0.01) the proliferation of fibroblasts cultured in the presence of serum. Day 5 cell culture supernatants showed a significant per cell increase in collagen type I (P < 0.05) and type III (P < 0.01) as measured by ELISA. Type I collagen production in exposed cells was 11.64 + 0.531 microgram/10(6) cell vs. 9.53 + 0.500 microgram/10(6) cells in unexposed cells. Type III collagen production was 0.601 + 0.012 microgram/10(6) cell in exposed cells and 0.247 + 0.008 microgram/10(6) cells in unexposed cells. mRNA levels were increased after a 4-day exposure to 10(-7) M 1,25-(OH)2D3 for both type I (2.5-5-fold) and type III (5.5-7.76-fold) collagen. These results suggest a novel effect of increased collagen production by dermal fibroblasts upon exposure to 1,25-(OH)2D3 that is independent of proliferation.

Autoradiography↗

PubMed1994

Fibroblast behavior in vitro is unaltered by products of staphylococci cultured from silicone implants.

Our previous clinical study supported the concept that capsular contracture is associated with subclinical infection of silicone implants. If bacterial presence, indeed, contributes to capsular contracture, then fibroblast behavior might be expected to change in the presence of bacteria by-products. Therefore, study of possible alteration of fibroblast behavior by bacteria products was undertaken using an in vitro model with cultured dermal fibroblasts. Coagulase-negative staphylococci from silicone mammary and penile implants were isolated and their phenotypic features were characterized. All represented nonbiofilm-producing strains. Products of isolate cultures were noncytotoxic and did not alter matrix reorganization (collagen gel contraction model) or collagen production by fibroblasts. Isolates from either mammary or penile implants exerted similar effects.

Breast↗

PubMed1994

[The degree of collagen crosslinks in medical collagen membranes determined by measuring their water absorption].

Collagen membranes were crosslinked by using three agents: glutaraldehyde, hexamethylene-diisocyanate, and UV irradiation. The increasing concentrations of above chemical agents or longer time of UV exposition resulted in the higher cross-links degree and in the decrease of collagen membranes swelling (measured as water absorption), their elasticity and mechanical resistance. According to American standards, the degree of collagen biomaterial cross-links is determined by measuring of the digestion time by pepsin. However, that method is very time-consuming. In our study, we have found that a simple, linear regression between logarithm of digestion time by pepsin exists and it was identical for all three cross-linking agents used. We have concluded that determination of water absorption can be an alternative, simple and fast method for examination of collagen membrane cross-links degree.

Absorption↗

PubMed1993

Synthesis and antibody-mediated detection of oligonucleotides containing multiple 2,4-dinitrophenyl reporter groups.

A series of non-nucleoside-based 2,4-dinitrophenyl (DNP) phosphoramidites have been prepared and used in the multiple labelling of oligonucleotides during solid-phase synthesis. The length of spacer arm between the DNP label and the oligonucleotide phosphate backbone, and the number of attached DNP groups have both been varied in order to determine the optimum conditions for anti-DNP antibody binding. Detection using enzyme-linked colorimetric techniques showed sensitivity equivalent to that obtainable using biotinylated oligonucleotides.

2,4-Dinitrophenol↗