Investigation of the awareness of the students of shiraz dental school concerning the patients' rights and the principles of ethics in dentistry.

STATEMENT OF PROBLEM: Deliberating the patients' rights is one of the major human ethical and legal principles which can be investigated through the agenda of professional and medical ethics.accordingly , the students of dentistry have to be educated about this issue and achieve the necessary skills in deliberating and concerning the patients' rights. PURPOSE: The present study aimed to investigate Shiraz dental students' awareness and attitude regarding the patients' rights as well as the principles of dental ethics in order to design methods for organizing and improving the ethics in dentistry. MATERIALS AND METHOD: The present descriptive-analytical study was conducted on 111 students of different departments of Shiraz Dental School. The study data were collected through a questionnaire designed based on the patients' rights charter in Iran, ADA ethical codes which are internationally acceptable in the field of dentistry, and the guidelines of the ministry of health, treatment, and medical education (No. 140588). Then, the data were entered into the SPSS statistical software and analyzed. RESULTS: Of all participants, 21.6% were men and 78.4% were women. According to the results, 71% of the students were acquainted with the patients' rights. In addition, the patients' characteristics, including gender and nationality, were not important for 58.6% of the students. CONCLUSION: The study findings showed that 71% of the participants were acquainted with the patients' rights Establishment of a comprehensive, integrated charter in Iran is needed. With rapid development of medical sciences, new issues appear which necessitate taking into account the mutual rights of the physicians, people, and patients.

Species differences in cis-elements of the proalpha1(I) procollagen promoter and their binding proteins.

Previous studies suggest that there may be species differences in the utilization of cis-elements of the type I collagen genes. The present study was designed to examine this possibility by focusing on two regions of the proalpha1(I) collagen promoter. One is the GC-rich A1 region (-194/168) that modulates transcriptional activity of the mouse promoter. The other contains a glucocorticoid response element (GRE) implicated in negative glucocorticoid regulation of the rat promoter. Unlike mouse A1 probes, probes representing the analogous human (-195/-168) and rat (-193/-179) regions failed to bind nuclear proteins in gel shift assays. Binding assays with mouse A1 probes containing base substitutions indicated that this behavior could be ascribed to five bases in the human, and two in the rat sequences. In addition, the pattern of expression of c-Krox, a protein that alters transcriptional activity via the mouse A1 element, differed in mouse and human tissues. Computer analysis revealed differences in the arrangement of GRE half-sites in human and rat proalpha1(I) collagen promoters. In a region of the human promoter (-700/673) analogous to the rat (-672/-633), there are three half-sites, each separated by two nucleotides, that cooperate in binding of glucocorticoid receptor. There also is a proximal half-site at position -335 of the human promoter that binds glucocorticoid receptor, but it is not present in the rat promoter. This study has defined several species-specific differences in the sequences and nuclear protein binding activity of regions involved in transcriptional activity of the proalpha1(I) collagen promoter. The results suggest that the A1 regions of the human and rat promoters examined here are unlikely to function as regulatory cis-elements, and they provide a framework for investigating the role of GREs in transcriptional regulation. They also suggest that species differences in cis-elements and transcription factors should be taken into consideration when using heterologous systems to study collagen gene regulation.

Vitamin C deficiency in guinea pigs differentially affects the expression of type IV collagen, laminin, and elastin in blood vessels.

Vitamin C deficiency causes morphologic changes in the endothelial and smooth muscle compartments of guinea pig blood vessels. Endothelial cells synthesize the basement membrane components, type IV collagen and laminin, and smooth muscle cells synthesize elastin in blood vessels. Therefore, we examined the possibility that vitamin C deficiency affects the expression of these proteins. Decreased expression of types I and II collagens in other tissues of vitamin C-deficient guinea pigs is associated with weight loss and the consequent induction of insulin-like growth factor binding proteins; thus we also used food deprivation to induce weight loss. Female guinea pigs received a vitamin C-free diet, supplemented orally with ascorbate. Vitamin C-deficient guinea pigs received the same diet but no ascorbate, and the food-deprived group received no food, but were supplemented with vitamin C. Concentrations of mRNAs for basement membrane components and elastin in blood vessels were measured by Northern blotting; overall basement membrane metabolism was assessed by measuring immunoreactive laminin and type IV 7S collagen in serum. Laminin mRNA in blood vessels and serum laminin concentrations were unaffected by vitamin C deficiency. Concentrations of type IV collagen and elastin mRNAs in blood vessels were not significantly affected in moderately scorbutic guinea pigs (0-7% weight loss), but with increased weight loss, type IV collagen mRNA was 57% (P < 0.05) and elastin mRNA was 3% (P < 0. 01) of normal values. In food-deprived guinea pigs, type IV collagen mRNA was 51% (P < 0.05) and elastin mRNA was 35% (P < 0.05) of normal. Serum type IV 7S collagen concentrations were 25% of normal in scorbutic guinea pigs with extensive weight loss. The lower expression of type IV collagen and elastin mRNAs in blood vessels may contribute to defects observed in blood vessels during scurvy.

Regulation and properties of bone alkaline phosphatase during vitamin C deficiency in guinea pigs.

The precise physiological role of alkaline phosphatase is unknown, although evidence suggests it is involved in bone mineralization. Previous studies showed that serum and bone alkaline phosphatase activity is decreased during vitamin C deficiency. Some effects of scurvy, such as inhibition of collagen synthesis, are related to weight loss and subsequent induction of insulin-like growth factor binding proteins and they can be duplicated in fasted guinea pigs receiving vitamin C. We found that decreased alkaline phosphatase activity in bone and serum during scurvy was not completely due to the "fasting effect" and that the decrease in serum was due to loss of bone isoenzyme activity. There also was a decrease in immunoreactive enzyme protein and alkaline phosphatase mRNA concentrations in bone of scorbutic animals, indicating that synthesis of the enzyme was inhibited. Sialylation and addition of the glycosylphosphatidylinositol anchor to the enzyme in bone tissue were not affected by scurvy. The concentration of mRNA for osteocalcin, a bone-specific marker, also fell during scurvy and to a much greater extent than either alkaline phosphatase or type I collagen mRNAs, while osteopontin mRNA concentrations increased. These results differ from the reported role of ascorbic acid on the pattern of expression of these proteins during differentiation of osteoblasts in culture. The decreased expression of collagen, alkaline phosphatase, and osteocalcin could explain the defects in bone caused by scurvy.

Gene expression of iron-related proteins during iron deficiency caused by scurvy in guinea pigs.

The regulation of expression of hepatic iron-related proteins was examined during iron deficiency caused by scurvy in guinea pigs. Previous studies showed that some effects of scurvy, such as suppression of collagen gene expression, result from events associated with weight loss. During the initial phase of scurvy when vitamin C is depleted but animals grow normally, serum iron levels decreased to 50% of normal. During the second phase of scurvy when animals lose weight, there was a further decrease in iron levels to 10-15% of normal. Serum transferrin levels increased during scurvy, but this increase was related neither to the rate of weight loss nor to hepatic transferrin mRNA expression, which decreased. Serum ferritin levels of diminished early in scurvy with a preferential loss of the L subunit. In liver, however, both ferritin animals gaining weight. Ferritin gene expression during vitamin C deficiency was correlated with serum ferritin levels in that the level of mRNA for the H subunit remained relatively constant while that of the L subunit decreased early. Transferrin receptor mRNA expression in liver was induced as soon as iron levels decreased early in scurvy, which is similar to results reported for iron-depleted cultured cells. In contrast to results in cell culture, expression of iron regulatory protein 1 mRNA was decreased to approximately 50% of normal early in scurvy with a concomitant decrease in hepatic cytosolic aconitase activity. Our data indicate that iron deficiency occurs early during vitamin C deficiency and leads to changes in expression of iron-related proteins that differ in some aspects from regulation by iron in cell culture. Other events associated with weight loss in late scurvy may play a further role in this regulation.

Modulation of native chondroitin sulphate structure in tissue development and in disease.

Chondroitin sulphate proteoglycans are synthesised by different tissues and cell types, and the chondroitin sulphate chains are variably sulphated. Three monoclonal antibodies 3B3, 7D4 and 6C3 that recognise different native chondroitin sulphate epitopes have been used to investigate changes in structure during embryonic tissue development in the chick and in the response of mature canine articular cartilage during experimental osteoarthritis. Strong focal expression of the epitopes was seen during development of chick bursa, which was different for the three epitopes and which changed during 5 days of development. In embryonic chick limb, although chondroitin sulphate is present throughout the cartilage, the 3B3 epitope, which is at the non-reducing terminus of chains, was only expressed on chondroitin sulphate within one region of the sub-articular cartilage. In mature canine articular cartilage the expression of this epitope on proteoglycans was very low, but when determined 3 or 6 months after induction of experimental osteoarthritis the level was greatly increased in all joints tested (23/23). The abundance of the other two native chondroitin sulphate epitopes was also increased in this experimental disease. The results show that expression of the chondroitin sulphate epitopes detected by the monoclonal antibodies changes during cellular differentiation and development and suggests that it is closely controlled by the cells synthesising chondroitin sulphate chains.

Identification of monoclonal antibodies that recognize novel epitopes in native chondroitin/dermatan sulfate glycosaminoglycan chains: their use in mapping functionally distinct domains of human skin.

Five monoclonal antibodies (MAb), 7D4, 4C3, 6C3, 4D3, and 3C5, were produced in mice immunized with high buoyant density embryonic chick bone marrow proteoglycans (PGs) as antigen. All of these MAb recognized epitopes in native chick bone marrow and cartilage PGs which could be selectively removed by chondroitinase ABC and chondroitinase AC II, indicating that their epitopes were present in chondroitin sulfate glycosaminoglycans (GAGs). These MAb recognized epitopes present in purified cartilage PGs obtained from a wide variety of different vertebrate species. However, none of the new MAb detected epitopes in Swarm rat chondrosarcoma PG. On the basis of these results, we propose that these MAb recognize novel epitopes located in chondroitin sulfate/dermatan sulfate glycosaminoglycan (CS/DS GAG) chains, representing at least four and possibly five different structures. Immunocytochemical studies have shown that the epitopes identified by these new MAb are differentially distributed in tissues. All of these MAb immunocytochemically detected epitopes in embryonic chick cartilage and bone marrow. Three of them (4C3, 7D4, and 6C3) recognized epitopes in adult human skin. All three detected epitopes in the epidermis, one (6C3) strongly detected epitopes in the papillary dermis, and two (4C3, 7D4) detected epitopes in the reticular dermis. Immunostaining patterns in skin using the new MAb directed against native CS/DS structures were distinctly different from those obtained using MAb against the common CS isomers. The distribution of these CS epitopes in functionally distinct domains of different tissues implies that these structures have functional and biological significance.

Immunochemical and biochemical comparisons between embryonic chick bone marrow and epiphyseal cartilage chondroitin/dermatan sulphate proteoglycans.

Chrondroitin sulphate proteoglycans obtained from embryonic chick bone marrow and epiphyseal cartilage were compared using immunochemical and biochemical analyses. Proteoglycans from each tissue, separated on CsCl density gradients, under dissociative conditions, into high (1.6 g ml-1), medium (1.5 g ml-1) and low (1.4 g ml-1) buoyant density fractions, were immunochemically analysed, using a panel of monoclonal antibodies that specifically recognize chondroitin 4-/dermatan sulphates, chondroitin 6-sulphate, keratan sulphate, the hyaluronate binding region present on connective tissue proteoglycans, and link protein. The same antibodies were used in Western blot analyses to detect intact proteoglycan monomers and core proteins that had been fractionated by agarose-polyacrylamide and by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Specific differences between marrow and cartilage proteoglycans were detected. In CsCl gradients, marrow proteoglycans displayed a higher degree of heterogeneity in terms of buoyant densities and hexuronate distribution. Keratan sulphate chains were constituents of the majority of 'large' proteoglycans in the marrow; however, a portion of the large proteoglycans in marrow middle buoyant density fraction either lacked keratan sulphate chains or were substituted with a form different from that found on cartilage proteoglycans. Marrow lacked 'small' chondroitin/dermatan sulphate proteoglycans that were present in cartilage and contained a more heterogeneous population of proteoglycans, particularly in the lower buoyant density fractions. Both marrow and cartilage were similar in that they contained, as their major components, large, aggregating proteoglycans and link proteins that were immunochemically and biochemically identical. The significance of these differences between marrow and cartilage proteoglycans remains to be determined, but they may, in part, be responsible for imparting unique characteristics to the haematopoietic extracellular matrices.

Epitope-specific changes in chondroitin sulfate/dermatan sulfate proteoglycans as markers in the lymphopoietic and granulopoietic compartments of developing bursae of Fabricius.

The types and distributions of chondroitin sulfate proteoglycans within developing chick bursae of Fabricius were determined by indirect immunocytochemical analyses using mAb specific for chondroitin/dermatan sulfate epitopes. Analyses obtained from the use of well characterized mAb known to specifically identify chondroitin 4- and dermatan sulfates (antibody 2B6) and chondroitin 6-sulfate (antibody 3B3) were compared with those obtained from two additional mAb raised against chick chondroitin sulfates proteoglycans derived from hemopoietic tissue. The results indicate that chondroitin sulfate compositions of the adjacent lymphopoietic and granulopoietic compartments differ. Chondroitin 6-sulfate, notably absent from lymphopoietic regions, is a major chondroitin sulfate species in granulopoietic regions of day 13 bursae. Moreover, chondroitin 6-sulfate disappears from the granulopoietic compartment in a time course that corresponds to the decline in granulopoietic activity. Simultaneously, there is an apparent increase in chondroitin sulfates associated with developing medullary regions of lymphoid follicles. The content of chondroitin 4-/dermatan sulfates and, most significantly, of chondroitin/dermatan sulfates identified by antibodies raised against chick proteoglycans, increases within developing follicles. As a consequence, by day 18 of incubation, immunostained follicles become clearly demarcated from the connective tissue of the tunica propria. This study provides evidence that chondroitin sulfates are constituents of both lymphopoietic and granulopoietic microenvironments and that subtle changes occur within these proteoglycan structures during bursal development. These developmental changes in chondroitin sulfate compositions are consistent with these molecules playing a functional role in hemopoiesis.

Immunochemical characterization and ultrastructural localization of chondroitin sulfates and keratan sulfate in embryonic chick bone marrow.

Monoclonal antibodies directed against specific carbohydrate epitopes on chondroitin 4-/dermatan sulfate, chondroitin 6-sulfate, keratan sulfate, and a monoclonal antibody directed against the hyaluronate binding region were used to characterize proteoglycans extracted from embryonic chick bone marrow. About half of the proteoglycans separate into the high density fraction on a CsCl gradient. Glycosaminoglycan-specific antibodies recognize proteoglycans from all fractions; this includes an antibody directed against keratan sulfate. Some proteoglycans, principally in the high buoyant density fraction, contain sites recognized by the antibody specific for the hyaluronate binding region. Within limits of detection, all core proteins belong to the high-molecular-weight category, with weights in excess of 212 kD. Antibodies directed against chondroitin 4-/dermatan sulfate and against keratan sulfate primarily bind to extracellular matrix material located in the extracellular spaces and to matrix elements in the pericellular regions of fibroblastic stromal cells. The antibody that recognizes chondroitin 6-sulfate binds to sites on surfaces of fibroblastic stromal cells and also to extracellular matrix material. Little or no antibody binding is detected on surfaces of granulocytic cells. These studies indicate that chondroitin sulfate and keratan sulfate chains are both present in the proteoglycan extract.