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Biomedical subjects

A Linde

Publications and source records attributed to A Linde.

At least 235 records · Page 13Linked to original sources
PubMed1988

Differences between non-collagenous protein content of rat incisor and permanent bovine dentin.

The content of non-collagenous proteins, extractable upon demineralization, in dentin from permanent bovine teeth and continuously growing rat incisors was compared. In both tissues, highly phosphorylated phosphoprotein and proteoglycan were major non-collagenous components. Whereas gamma-carboxyglutamate-containing proteins of the osteocalcin type constituted a major fraction in rat dentin, these were virtually absent from bovine dentin. The two tissues differed in content and composition of phosphoproteins, the major non-collagenous protein fraction of dentin. Considerable differences were also found in the presence of other acidic non-collagenous proteins. It was concluded that the general non-collagenous protein composition of dentin from different species may differ fundamentally, but that such differences may be advantageous in exploring the different roles of specific components in the mechanism of biomineralization.

Amino Acids↗
PubMed1988

'On-off' phenomenon in Parkinson's disease: relationship between dopa and other large neutral amino acids in plasma.

Administration of a low-protein diet to parkinsonian patients with "on-off" syndromes consistently increased the total daily time of "on" states when compared with a high-protein diet. The clinical effect of the low-protein diet may be due to a marked decrease in the plasma concentration of large neutral amino acids that compete with L-dopa for carrier-mediated transport into the brain.

Aged↗
PubMed1987

Subclass reactivity to Epstein-Barr virus capsid antigen in primary and reactivated EBV infections.

A new method for analysis of virus-specific Immunoglobulin G (IgG) subclasses was developed using indirect immunofluorescence. Three hundred thirty-three serum samples from patients with different types of Epstein-Barr virus (EBV)-associated diseases and healthy controls were examined for subclass distribution to the virus capsid antigen (EBV VCA). EBV-VCA-expressing cell preparations were incubated with patient serum followed by monoclonal antibodies to human IgG1 through IgG4 and labelled anti-mouse IgG. Virus-specific IgG1 was found to be the dominant antibody. The titers for IgG1 and total Ig to EBV VCA correlated well. EBV VCA-specific IgG2 was not found. EBV VCA-specific IgG3 in a titer of greater than or equal to 10 was found in 33% of healthy seropositive donors, in 97% of patients with suspected reactivated EBV infection, and in 100% of symptomatic patients with suspected reactivated EBV infection. EBV VCA specific IgG3 occurred in 90% of placebo-treated compared to 30% in long-term acyclovir-treated bone marrow transplant recipients, indicating more frequent reactivations in the former group. IgG4 to VCA was infrequently found in seropositive persons. In serum samples from patients with nasopharyngeal carcinoma and high EBV VCA Ig and IgA titers, IgG4 to VCA was always present. Analysis of EBV VCA specific IgG subclasses seems to be valuable for the diagnosis of reactivated EBV infection.

Adolescent↗
PubMed1987

Regulation of free Ca2+ by subcellular fractions of rat incisor odontoblasts.

A miniaturized Ca2+ electrode system was developed to monitor small and fast fluctuations of Ca2+ activity in the micromolar range in 100 microliters volumes. This was used to study Ca2+ influx/efflux cycling in suspensions of rat-odontoblast and liver-cell mitochondria and microsomes, as well as in whole odontoblasts with plasma membranes made permeable by digitonin. The steady-state free-Ca2+ activity maintained by mitochondria was pCa 6.2-6.4, and that of microsomes pCa 6.4-6.6. These levels were held upon repeated additions of Ca2+ and EGTA. The odontoblast mitochondria and microsomes had an intracellular Ca2+ buffering capacity similar to that of liver cells. The steady-state pCa level maintained in suspensions of digitonin-permeabilized whole odontoblasts was 6.4-6.6. Thus, this study gave no evidence for any specialized intracellular handling of Ca2+ in cells involved in mineralization.

Animals↗
PubMed1987

Hormonal influence on glycosaminoglycan synthesis in uterine connective tissue of term pregnant women.

Adaptation of the uterus to the growing fetus necessitates remodelling of the uterine connective tissue. Proteoglycans, being a main constituent of the extracellular matrix, influence the physical properties of the tissue and play an important regulatory role for a number of functional events. The synthesis of glycosaminoglycans (GAGs), the carboxyhydrate side chains of proteoglycans, in tissue from the lower uterine segment of term pregnant women was investigated in vitro by measurement of 35SO4 and [14C]glucosamine incorporation. Prostaglandin E2 and oestradiol-17 beta significantly increased the synthesis of sulphated GAGs but decreased the incorporation of [14C]glucosamine, while relaxin, prostaglandin F2 alpha and oxytocin had no significant effect. To further explore the influence of prostaglandin E2, tissue specimens were incubated with [14C]glucosamine and GAGs separated into three fractions on cetylpyridinium chloride cellulose micro columns. Prostaglandin E2 was found to significantly reduce the synthesis of components recovered in the glycoprotein and hyaluronate fractions, whereas synthesis of components in the sulphated GAG fraction was increased. The results indicate that prostaglandin E2 and oestradiol-17 beta have differential effects on different GAGs whereas relaxin, oxytocin and prostaglandin F2 alpha have no effect.

Connective Tissue↗
PubMed1987

Influence of steroid hormones on the incorporation of amino acids in uterine and cervical tissue of pregnant women.

The influence of steroids on protein synthesis in cervical and uterine tissue obtained from early and term pregnant women was studied by measuring the incorporation of labelled amino acids into total protein. It was found that oestradiol-17 beta and progesterone significantly reduced the incorporation of [3H]proline. Androstenedione and cortisol had no significant effect on the incorporation of [3H]proline even at high concentrations. The protein synthesis inhibitors puromycin and cycloheximide blocked the incorporation of [3H]proline to 80-85%. However, there was no further reduction in the incorporation in the presence of oestradiol. Oestradiol was found to reduce the incorporation of [14C]glycine but not that of [3H]serine. The results indicate that oestradiol and progesterone reduce protein synthesis in human cervical and uterine tissue and that this reduction, at least partially, involves collagen synthesis. Oestradiol and progesterone were equipotent under in vitro experimental conditions. The tissue concentration of progesterone in the pregnant uterus is, however, much higher than that of oestradiol. It seems therefore probable that progesterone rather than oestradiol restricts unopposed synthesis of proteins, presumably mainly collagen.

Amino Acids↗
PubMed1987

Amantadine for prophylaxis against influenza A.

Amantadine, 200 mg daily, for 5 days was used in an attempt to restrict the spread of influenza A in a hospital ward. After index cases of influenza A amantadine was given to 2 patients with clinical symptoms and to 8/10 patients who were not yet ill. No further case of clinical influenza was seen among the patients, but 3 of those receiving amantadine developed subclinical infection. No side effects of amantadine were noted. Amantadine was not given to any of the 23 hospital staff on duty. In this group 8 cases of influenza A appeared, 3 of them during the week after the introduction of amantadine to patients.

Amantadine↗
PubMed1987

Postpartum activation of autoimmunity: transient increase of total IgG levels in normal women and in women with autoimmune thyroiditis.

The immunoregulatory mechanisms underlying the transient rebound of autoimmune disease activity in the postpartum period were studied by determining serum immunoglobulins, thyroid microsomal antibodies and some viral (cytomegalovirus, Epstein-Barr, varicellae-zoster and mumps) and bacterial (Yersinia enterocolitica and Salmonella) antibodies in women with autoimmune thyroiditis and in healthy postpartum women. A characteristic increase between 2 and 5 months postpartum followed by a decrease to 10-12 months postpartum was observed not only for thyroid microsomal antibody titres in women with autoimmune thyroiditis but also for serum total IgG and IgG subclass levels (but not IgM, IgA or IgE) in both groups of women. This pattern of transient antibody increase was not detected against viral and bacterial antigens. The characteristic alterations of thyroid microsomal antibody titres in the postpartum period of women with autoimmune thyroiditis thus appear to occur as a consequence of an activation of immunoglobulin-producing B cell clones. This activation seems restricted to the IgG class and to certain B cell clones.

Adult↗
PubMed1986

Reduction of dental fear: psychophysiological correlates.

EMG, HR and SCR were continuously recorded during two Standardized Dental Examinations (SDE) of 15 dental phobics. Following the first SDE, the patients were assigned to two treatment groups, one receiving systematic desensitization followed by two separate amalgam restorations and one premedicated with Valium for the two restorations. The dentist rated the patients' behavior on a 5-point scale. Corah's Dental Anxiety Scale (DAS) was used prior to the first SDE and following the second SDE. The second SDE was conducted on a separate occasion following the second restoration. No significant correlations were found between any of the physiological measures and either the dentist's ratings or the second DAS or DAS change scores. Significant differences found between the two treatment groups on the dentist's ratings, second DAS, and change scores were not reflected by the physiological measures.

Adult↗
PubMed1986

Ability of oral bacteria to degrade fibronectin.

The fibronectin-degrading ability of 116, mainly oral, strains was assayed by using plasma-derived fibronectin adsorbed to a polystyrene surface. Ability to degrade fibronectin was revealed in strains of Bacteroides gingivalis, Bacteroides intermedius, Bacteroides loeschii, Staphylococcus aureus, Staphylococcus epidermidis, Peptococcus prevotii, Clostridium sporogenes, and Propionibacterium acnes. The fibronectinolytic activity of subgingival bacteriological samples was found to be related to the presence of B. gingivalis and B. intermedius. In addition, strains of the nonoral Bacteroides species B. asaccharolyticus and B. fragilis showed fibronectin-degrading ability. No such ability was detected in the oral strains tested of Streptococcus, Veillonella, Actinomyces, Lactobacillus, Actinobacillus, Capnocytophaga, Fusobacterium, or Haemophilus species.

Bacteria↗
PubMed1985

Sensitive analytic ELISAs for subclass herpes virus IgG.

The subclass distribution of antiviral antibodies to three herpes viruses was studied in a population of healthy blood donors. Subclassification by monoclonal antibodies led to the identification of certain viral IgG patterns. IgG1 appeared to be formed in response to almost all CMV, HSV-1 and VZV infections. A higher frequency of virus-specific IgG3 to CMV and HSV-1 suggested that these infections may be reactivated subclinically more often than VZV. The presence of CMV and VZV IgG4 showed a familial relationship, while IgG4 responses to HSV-1 were common. Persons with IgG4 as the only subclass-reactive antibody to CMV showed cell-related reactivities in a high frequency. Patients with leukemias, myelomas and Crohn's disease had a near-normal subclass pattern to the herpes viruses.

Antibodies, Viral↗
PubMed1985

Alterations in fibronectin distribution in oral mucosal vesiculo-bullous lesions.

The distribution of fibronectin in human oral mucosal vesiculo-bullous diseases was studied by indirect immunofluorescence. Subepithelial (benign mucous membrane pemphigoid and erythema multiforme) as well as intraepithelial (pemphigus vulgaris and dyskeratosis follicularis) lesions were selected. A marked accumulation of fibronectin was generally found in the lamina propria and basement membrane region, except in dyskeratosis follicularis. Intraepithelial staining occurred in erythema multiforme and dyskeratosis follicularis. In pemphigus vulgaris intercellular staining was seen in relation to acantholysis. Both mucous membrane pemphigoid and erythema multiforme showed a linear accumulation corresponding to the intact basement membrane. However, only pemphigoid lesions disclosed fibronectin on the epithelial side of the vesicles.

Darier Disease↗
PubMed1985

Rapid viral diagnosis of acute respiratory infections: comparison of enzyme-linked immunosorbent assay and the immunofluorescence technique for detection of viral antigens in nasopharyngeal secretions.

Nasopharyngeal secretions from adults and children were obtained in Stockholm, Sweden, for routine diagnosis of influenza A virus, influenza B virus, respiratory syncytial (RS) virus, parainfluenza type 3 virus, and adenovirus infections by demonstration of viral antigens directly in the specimens. The cells in nasopharyngeal secretions were pelleted by centrifugation for preparation of cell deposits for diagnosis by the immunofluorescence technique (IF) in London, England, and in Stockholm, whereas the supernatants were used to diagnose infection by the enzyme-linked immunosorbent assay (ELISA) in Stockholm. Titrations of the various purified viruses showed that ELISA could detect viral antigens in amounts corresponding to 1 to 10 ng of virus protein per test well. In a series of 73 specimens tested for influenza A, RS, and parainfluenza type 3 viruses by IF in London and by ELISA in Stockholm, 15 of 18 RS, 14 of 15 influenza A, and 2 of 2 parainfluenza type 3 viral infections were diagnosed by ELISA as compared with IF, giving sensitivities for RS and influenza A viral diagnosis of 83 and 93%, respectively, and a specificity of 100%. In another series of specimens from 35 patients tested for influenza B virus and adenovirus, five influenza B virus and four adenovirus infections were diagnosed by both methods; one additional influenza B infection was detected only by IF and another only by ELISA. Comparisons of diagnostic results between the two methods performed in Stockholm gave nonagreement of results for 37 of 1,593 tests (2.5%) for the five viruses. The conclusion reached was that the described ELISA, although a satisfactory test, had somewhat less sensitivity than did IF for the detection of respiratory viral infections. This could possibly be explained by unnecessary dilutions of specimens at the time of collection; transportation, processing, and storage of specimens were less complicated than for IF.

Adenoviridae Infections↗
PubMed1985

The extracellular matrix of the dental pulp and dentin.

The dental pulp is a loose connective tissue, characterized by its specific anatomical location. Its extracellular components are obvious subjects for study, since such components are largely responsible for the physiological properties of the tissue. Several clinically important processes occur extracellularly, e.g., defense mechanisms such as inflammatory reactions and formation of calcified tissue. The dental mesenchyme has a crucial role during early tooth morphogenesis. The dental pulp, or rather the dental papilla, seems to have only an indirect role during dentinogenesis. This review discusses proteoglycans and glycosaminoglycans, fibronectin and other non-collagenous proteins, and the different types of collagen that have been studied in pulp connective tissue. With regard to its biochemical constituents, the pulp is similar to other loose connective tissues. Collagen type I is the major fibrous component, but collagen type III also constitutes a large portion. Fibronectin is present, as is a high content of proteoglycan. In the proteoglycans, all normally occurring connective tissue glycosaminoglycans can be demonstrated. The composition of the pulpal extracellular matrix during tooth development is quite different from that of the mature tooth. Thus, it is important not to draw any too-far-reaching conclusions about the situation in human pulp from results obtained by studying pulp from animal teeth with ongoing dentinogenesis. In spite of their common ancestry, pulp and dentin differ considerably in extracellular matrix composition. Proteoglycans and collagen type I are present in dentin. No type III collagen or fibronectin can be found in the dentin, although it is present in the dental pulp.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Surface features of human natural killer cells and antibody-dependent cytotoxic cells.

The purpose of the present study was to examine the surface features of purified large granular lymphocytes (LGLs) (natural killer (NK) cells, antibody-dependent cytotoxic lymphoid (ADCL) cells, K-cells, Fc gamma (+) third population (non-T, non-B) lymphoid cells, T gamma cells) by scanning electron microscopy (SEM) and to compare their surface features with granulocytes, monocytes and Fc gamma (-) lymphoid cells that were all fixed for SEM under identical conditions. We have determined that 72-80% of LGLs enriched by rosette formation with sensitized erythrocytes or using Percoll gradients, have a complex microvillous surface (CMS) pattern identical to that of lymphocytes. The LGL fraction appears by SEM to represent a morphologically homogeneous population of cells. Monocytes prepared for SEM under identical conditions had distinct surface folds and granulocytes displayed numerous broad-based ridge-like profiles. The majority of lymphoid cells in an unfractioned population have a CMS pattern when incubated at room temperature (25 degrees C) before fixation, and a sparse microvillous surface (SMS) pattern when incubated at body temperature (37 degrees C). Ficoll-Hypaque (FH) also had a direct effect on the cell surface pattern. Over half of the unfractionated lymphoid cells displayed a CMS pattern after cells were washed free of FH and incubated at 37 degrees C before fixation. The CMS pattern is therefore not unique to LGLs but can be produced by the surface alteration of non-LGLs found in unfractionated buffy coat and mononuclear fractions. The interactions between LGLs and sensitized erythrocytes in an antibody-dependent cytotoxic assay system, and LGLs and K562 target cells in an NK assay system, were also examined. This is the first report that describes the surface features of human LGLs interacting with K562 target cells in an NK assay system. The LGL populations studied by SEM were determined to have a high percentage of Leu-11(+) and Leu-7(+) cells. These same population were also shown to have high antibody-dependent cytotoxicity and NK activity using the 51Cr release assay.

Cell Fractionation↗