Increased risk of non-hematological cancer in young patients with aortic stenosis: a retrospective cohort study

Background

We have previously reported an increased risk for non-hematological malignancies in young patients with moderate or severe aortic stenosis (AS) (1). These findings were the result of a post-hoc analysis from a large echocardiography database and needed verification.

Purpose

To determine, using a different study population, whether young patients with AS are at increased risk for cancer.

Methods

A large echocardiographic database was used to identify patients (age≥20 years) with moderate or severe AS (study group) and patients without aortic stenosis (comparative group). The new occurrence of non-hematological malignancies was determined after the index date (first echo with moderate or severe AS or first recorded echo in the control group).

Results

The final study group included 7,013 patients with AS and 98,884 without AS. During a median follow-up of 6.9 years (3.0–11.1) there were 10,705 new cases of non-hematological cancer. The crude incidence rate of cancer was higher in AS compared to non-AS patients (22.3 vs. 13.7 per 1,000 patient-year, crude HR 1.58 (95% CI 1.46–1.71). After adjustment for relevant covariates, there was no difference between groups (HR 0.93, 95% CI 0.86–1.01). Only patients in the lowest age quartile (20–49.7 years), had an increased adjusted risk of cancer (HR 1.91, 95% CI 1.08–3.39). The HR for the risk of cancer in AS was inversely proportional to age (P<0.001 for the interaction between AS and age) (Figure 1).

Conclusion

Young patients with moderate or severe AS are at increased risk for cancer. Cancer surveillance should be considered for young patients with AS.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Does global longitudinal strain predict long-term outcome in patients presenting to the emergency department with chest pain?

Funding Acknowledgements

Type of funding sources: None.

Background

 Two-Dimensional Strain for Diagnosing Chest Pain in the Emergency Room (2DSPER) was a prospective multicenter study designed to determine whether 2D longitudinal strain (2DLS) can assist in triage of patients with chest pain in the emergency department (ED). In that study 2DLS was not useful to rule out acute coronary syndromes (ACS) in the ED, partly because many patients without ACS had abnormal 2DLS. The prognostic significance of 2DLS in these patients is unclear.

The aim of the current study was to determine whether global longitudinal strain (GLS), measured using 2D echocardiography in the ED, can predict long-term outcome.

Methods

 Long-term (median 7.7 years [IQR 6.7-8.2]) major adverse cardiac events (MACE; cardiac death, ACS, revascularization, hospitalization for heart failure or atrial fibrillation) was available in 525 of 605 patients (87%) enrolled in the 2DSPER study. The study prospectively enrolled patients presenting to the ED with chest pain and suspected ACS but without a diagnostic ECG or elevated troponin. Global longitudinal strain (GLS) was computed from echocardiograms performed within 24 hours of chest pain using a dedicated 2DLS software (EchoPAC SW; GE Vingmed Ultrasound AS). MACE of patients with worse GLS (>median) was compared to those with better GLS (≤median).

Results

 Median GLS was -18.8%. MACE occurred in 43/249 (17.3%) of patients with worse GLS (-16.8 ± 1.5) as compared with 49/276 (17.8%) with better GLS (-20.8 ± 1.6), HR 0.98 (95%CI 0.65-1.4, p = 0.9) (Figure). Similarly, there was no significant difference in total mortality (6% vs. 4.7%, p = 0.5), cardiac death (0.4% vs. 0.7%, p = 0.6), ACS (8% vs. 8.3%, p = 1), revascularization (10% vs. 10.9%, p = 0.8), hospitalization for heart failure (0.8% vs. 2.2%, p = 0.2) or atrial fibrillation (3.6% vs. 4.3%, p = 0.7) between groups. Predictors of MACE were male gender (HR 2.5, 1.4-4.3, p = 0.02), history of coronary artery disease (HR 3.3, 2-5.4, p < 0.0001) and hypertension (HR 1.8, 1.2-2.8, p = 0.005), but not GLS (HR 0.98, 0.7-1.5, p = 0.9).

Conclusions

 GLS did not predict long term outcome in patients presenting to the ED with chest pain. Long-term outcome was favorable in the group of patients with worse GLS, similar to better GLS.

Abstract Figure.

The CEA Family: A System in Transitional Evolution?

The CEA family consists of two structurally and functionally distinct subgroups; the group including CEA, NCA and CGM-6 which are cell surface-bound by phosphatidylinositol (PI) linkages, and the group of BGP splice variants which have transmembrane and cytoplasmic domains. Although all CEA family members mediate intercellular adhesion in vitro, the PI-linked group show Ca++ and temperature independent adhesion whereas the BGP group show rapidly reversible Ca++ and temperature dependent adhesion. From the close alignment in cDNA nucleotide sequences between family members and between repeated domains in one family member, it is apparent that the CEA family is now rapidly evolving; in fact, analogs of only the transmembrane BGP group have been found so far in the mouse. The addition of a new group of potent adhesion molecules to complex species at some time after the rodent radiation has strong evolutional implications, which are discussed.

[Assessment of pulps vitality for children and adolesents]

Accurate assessment of pulp status is one of the greatest diagnostic challenges in clinical practice. This may be further complicated in children and adolescent where the practitioner is faced with different situations such as: primary teeth, developing permanent dentition, traumatized teeth, patients undergoing orthodontic treatment. In addition, the dentist is frequently faced with young children who have limited ability to recall a pain history or cooperate with the test itself. A variety of pulp testing approaches exist, and there may be a confusion as to their validity in different clinical situations. Sensitivity tests include thermal testing and Electric Pulp Test. Their limitation is the possibility to get false positive or false negative results. Their primary limitation lies in the fact that they test the sensory response of the tooth, which can be temporarily lost after dental trauma. A more accurate assessment of pulp vitality would be made by determining the presence of a functioning blood supply with the use of Laser Doppler Flowmetry or Pulse Oximetry. This paper provides the clinician with a comprehensive review of current pulp testing methods and allow greater insight into the interpretation of pulp testing results, especially in young patients.

The human tuftelin gene and the expression of tuftelin in mineralizing and nonmineralizing tissues

Tuftelin has been suggested to play an important role during the development and mineralization of enamel, but its precise function is still unclear. This article reviews major milestones in the discovery, structural characterization, expression, localization, and conservation of tuftelin in different vertebrate species. It focuses on the structure of the human tuftelin gene, which has recently been deciphered [12]. It describes the exon-intron organization, sizes and structure, the promoter structure, and the newly discovered alternatively spliced human tooth-bud tuftelin mRNA transcripts. It also examines information on the structural motifs in the human-derived tuftelin protein and how they relate to tuftelin from other species. It reviews our recent results on the transcription of tuftelin mRNA and protein expression in several nonmineralizing soft tissues, using reverse-transcription polymerase chain reaction (RT-PCR) followed by DNA cloning and sequencing, indirect immunohistochemistry, immunohistochemistry combined with confocal microscopy, and in situ hybridization. These results and earlier Northern blot results show that tuftelin, in addition to being expressed in the developing and mineralizing tooth, is also expressed in several nonmineralizing soft tissues, suggesting that tuftelin has a universal function and/or a multifunctional role.

Self recognition in the Ig superfamily. Identification of precise subdomains in carcinoembryonic antigen required for intercellular adhesion

The homophilic binding of extracellular domains of membrane-bound immunoglobulin superfamily (IgSF) molecules is often required for intercellular adhesion and signaling. Carcinoembryonic antigen (CEA), a member of the IgSF, is a widely used tumor marker that functions in vitro as a homotypic intercellular adhesion molecule. CEA has also been shown to contribute to tumorigenicity by inhibiting cellular differentiation, an effect that requires the homophilic binding of its extracellular domains. It was of interest, therefore, to identify small subdomain sequences in CEA that could serve as a focus in the design of peptides that disrupt CEA-mediated intercellular adhesion. Three subdomains in the N-terminal domain of CEA, identified by site-directed deletions and point mutations, were shown to be required for intercellular adhesion. Cyclized peptides representing two of these subdomains, (42)NRQII and (80)QNDTG, were found to be effective in blocking CEA-mediated cellular aggregation when added to CEA-expressing transfectants in suspension. Intermolecular binding involving each of these subdomains is therefore essential for intercellular adhesion and cannot be compensated for by known binding contributions of other regions in the CEA molecule. In further support of this assumption, the binding epitope of an anti-CEA monoclonal antibody (monoclonal antibody A20) known to block CEA-mediated adhesion, was shown to bridge two of the three required subdomains: (42)NRQII and (30)GYSWYK.

Assessing the interpretation of criteria for clinical trial eligibility: a survey of oncology investigators

OBJECTIVE

To investigate whether eligibility criteria that exclude the elderly, persons with psychiatric disease, and persons with substance abuse problems from participation in randomized controlled trials (RCTs) are subjective and hence a source of variability in enrolment decisions and investigator uncertainty.

DESIGN

Survey questionnaire.

PARTICIPANTS

Cancer investigators from the United States and Canada.

INTERVENTIONS

Investigators were presented with clinical vignettes from 3 patient categories--eligible, ineligible and uncertain--for each of 5 eligibility criteria--3 subjective and 2 objective--and were asked whether they would enrol the patient in a trial and how sure they were of this decision. Demographic characteristics of the investigators were also collected.

OUTCOME MEASURES

The difference in enrolment decisions between subjective and objective criteria, and the difference in the certainty associated with these decisions.

RESULTS

Of 365 questionnaires sent out, 224 usable ones were returned. Compared with the objective criteria, the subjective criteria were associated with more variable enrolment decisions (p = 0.07 for the "eligible" scenario and p = 0.0001 for the "ineligible" and "uncertain" scenarios), and investigators were less sure about the decisions they made (p = 0.0001 for all scenarios). Demographic characteristics of the investigators failed to explain the observed differences.

CONCLUSIONS

Subjective eligibility criteria may interfere with the conduct and interpretation of RCTs and, therefore, their use ought to be justified explicitly in the study protocol. RCT designers, funding agencies and research ethics boards have an important role in reviewing eligibility criteria for their necessity.

A study in contrasts: eligibility criteria in a twenty-year sample of NSABP and POG clinical trials. National Surgical Adjuvant Breast and Bowel Program. Pediatric Oncology Group

We studied changes in eligibility criteria--the largest impediment to patient accrual--in two samples of clinical trials. Trials from the NSABP (National Surgical Adjuvant Breast and Bowel Program) and POG (Pediatric Oncology Group) were analyzed. After eliminating duplications, the criteria in each protocol were enumerated and classified according to a novel schema. NSABP trials contained significantly more criteria than POG trials, and added precision criteria (making study populations homogeneous) at a faster rate than POG studies. The difference between NSABP studies (explanatory trials) and POG studies (pragmatic trials) suggest that large numbers of eligibility criteria are not necessary for quality studies. We recommend that: (1) the inclusion/exclusion criteria distinction be abandoned; (2) eligibility criteria be explicitly justified; (3) the need for each criterion be assessed when new trials are planned; (4) criteria in phase III trials restricting patient accrual be minimized; and (5) further research be done to assess the impact of criteria on generalizability.

Long-term follow-up of conservative treatment of severely traumatized maxillary incisors

We present the case of a 26-year-old man who at the age of 9 suffered severe trauma to both maxillary central incisors. The underlying malocclusion was skeletal and classified as dental Class II/1 with severe crowding. Both the maxillary central incisors and the two lower first premolars were extracted and the patient was treated with an edgewise appliance for 2 years. Acceptable occlusal relationships were achieved following orthodontic and adjunctive treatment which consisted of reshaping the maxillary lateral incisors with composite materials and grinding the canines to resemble lateral incisors. A critical evaluation of the esthetic and functional results at the age of 26 years is presented.

What difference does it make to be treated in a clinical trial? A pilot study

OBJECTIVE

Pilot study to characterize treatment differences between patients treated in clinical trials and those treated in a clinical setting. Previous studies have shown higher survival rates for participants in trials of cancer therapy. This difference is observed even after rates are adjusted for important covariates such as age and stage of disease.

DESIGN

Retrospective chart review.

SETTING

Oncology outpatient department in a tertiary care hospital.

PATIENTS

Ninety women 18 to 70 years of age with early-stage breast cancer who were diagnosed in 1990. Fifty-one of the women were treated through clinical trials and 39 were treated outside of clinical trials.

OUTCOME MEASURES

Number of blood tests, telephone calls, clinic visits and imaging procedures as well as intensity of chemotherapy and use of radiation therapy. The age of the patient and the stage of disease were important covariates.

RESULTS

After the analysis was controlled for patient age and stage of disease, patients treated through a clinical trial were more likely to receive standard-dose chemotherapy (p = 0.020, 95% confidence interval 1.20 to 200.73) and more frequent blood tests (p < 0.001, 95% confidence interval 1.02 to 1.13) than other patients treated in the clinic.

CONCLUSIONS

Our results provide a plausible mechanism for the observed survival advantage for participants in clinical trials in oncology. Further study is called for. If these results are confirmed, they have important implications for informed consent to participate in clinical trials and for clinical practice.

Monitoring clinical research: an obligation unfulfilled

The revelation that data obtained for the US-based National Surgical Adjuvant Breast and Bowel Project (NSABP) from subjects enrolled at Hôpital Saint-Luc in Montreal was falsified has eroded public trust in research. Institutions can educate researchers and help prevent unethical research practices by establishing procedures to monitor research involving human subjects. Research monitoring encompasses four categories of activity: annual reviews of continuing research, monitoring of informed consent, monitoring of adherence to approved protocols and monitoring of the integrity of data. The authors describe characteristics of research projects that may call for monitoring procedures in each category. The form taken by such monitoring depends on the nature of the protocol. Although appropriate research monitoring requires substantial investment of personnel and financial resources, it is required under guidelines regulating research involving human subjects in Canada. Research monitoring is a step forward in re-establishing public confidence in medical research.

Recombinant haplotype bearing the lymphopenia gene of the BB rat

The development of insulin-dependent diabetes mellitus in the BB rat requires the presence of the class II major histocompatibility complex alleles of the RT1u haplotype and a T cell lymphopenia. The lymphopenia gene (lyp) behaves as an autosomal recessive trait that co-segregates with markers of rat chromosome 4. The current study examines two congenic and four recombinant inbred rat strains derived from BB and Buffalo rat strains using markers for simple-sequence length polymorphisms to confirm the linkage of the lymphopenia gene to chromosome 4. In two of these lines the lymphopenia associates with a recombinant haplotype that is BB-like at the D4Mit6 marker and Buffalo-like at D4Mit7 (neuropeptide Y locus) thus placing the lyp locus between these two closely linked markers.

Opposite functions for two classes of genes of the human carcinoembryonic antigen family

The human carcinoembryonic antigen (CEA) family can be divided into two subgroups according to the means of anchorage of member glycoproteins to the cell membrane: glycophosphatidyl inositol (GPI) linkage and transmembrane linkage. The GPI-linked members tend to be up-regulated in human tumours, whereas the transmembrane-linked members tend to be down-regulated. Thus the question as to whether the GPI members could be formally considered to function as oncogenes and the transmembrane members as tumour suppressors deserves consideration. Members of both subgroups function in vitro as intercellular adhesion molecules, but the characteristics of this adhesion, including temperature and divalent-cation dependence, differ markedly between the groups. Even the mechanism of intermolecular adhesion appears to differ fundamentally in that GPI-linked CEA-CEA binding involves a double reciprocal bonding between two domains, whereas transmembrane-linked biliary glycoprotein (BGP)-BGP binding requires only one domain. Finally, the ectopic expression of CEA in myoblasts can block myogenic differentiation leaving the cells with the ability to divide, while expression of BGP does not affect or may even accelerate myogenic differentiation. These differences in phenotypic effects in vitro thus mirror the differences observed in expression in tumours and support the view that the GPI and transmembrane groups have opposite effects on cells in relation to the malignant phenotype.

Haplotype mapping and sequence analysis of the mouse Nramp gene predict susceptibility to infection with intracellular parasites

The mouse chromosome 1 locus Bcg (Ity, Lsh) controls the capacity of the tissue macrophage to restrict the replication of antigenically unrelated intracellular parasites and therefore determines the natural resistance (BCG-R, dominant) or susceptibility (BCG-S, recessive) of inbred mouse strains to infection with diverse pathogens, including several Mycobacterium species, Salmonella typhimurium, and Leishmania donovani. We have used a positional cloning strategy based on genetic and physical mapping, YAC cloning, and exon trapping to isolate a candidate gene for Bcg (Nramp) that encodes a predicted macrophage-specific transport protein. We have analyzed a total of 27 inbred mouse strains of BCG-R and BCG-S phenotypes for the presence of nucleotide sequence variations within the coding portion of Nramp and have carried out haplotype typing of the corresponding chromosome 1 region in these mice, using 11 additional polymorphic markers mapping in the immediate vicinity of Nramp. cDNA cloning and nucleotide sequencing identified 5 nucleotide sequence variations within Nramp in the inbred strains; while 4 of these represented silent sequence polymorphisms, one G to A substitution at nucleotide position 783 resulted in the non-conservative replacement of Gly105 to Asp105 within the second predicted transmembrane domain (TM2) of the Nramp protein. An absolute association of this allelic variation and Bcg phenotype was observed in the 20 BCG-R strains (Gly105) and 7 BCG-S strains (Asp105) tested. Moreover, sequence analysis of the corresponding region of the Nramp gene from distantly related species indicated strong amino acid sequence conservation of TM2, including an invariant glycine at position 105. Haplotype mapping using sequence polymorphism identified within Nramp and additional RFLPs and SSLPs from the region revealed that although the 20 BCG-R strains analyzed showed diverse allelic combinations for these markers, the 7 BCG-S strains tested share a conserved core haplotype of 2.2 Mb overlapping and including Nramp. Taken together, these results suggest that (1) Gly105 is the wildtype form of Nramp and that the nonconservative substitution to Asp105 underlies the BCG-S phenotype, and (2) Bcg8 alleles carry the same Gly105-->Asp105 mutation and are identical by descent.

The duty to exclude: excluding people at undue risk from research

The clinical trial is the major investigational tool of clinical medicine. Two recent reports highlight the fact that the most often quoted mechanisms for the protection of research subjects, viz., research ethics board review and eligibility criteria, are insufficient to achieve this end. In this paper, we argue that the prime mechanism for the protection of persons in clinical trials should be the clinical judgement of the physician-investigator. The clinical investigator has a duty to protect subjects from both harm and undue risk. It is argued that the clinical investigator has a duty to screen for, and exclude, potential research subjects who may be unduly vulnerable to the risks of a particular clinical trial. In order to fulfill this obligation, the investigator should personally screen each potential research subject at the time of accrual. In larger trials in which this is not feasible, this task could be delegated to another appropriately qualified health care professional, with the principal investigator retaining personal responsibility. To reinforce and make explicit this legal and moral duty, we propose that the investigator sign a statement, appended to each subject's consent form, to attest that this duty has been responsibly discharged.

Human carcinoembryonic antigen, an intercellular adhesion molecule, blocks fusion and differentiation of rat myoblasts

Human carcinoembryonic antigen (CEA), a widely used tumor marker, is a member of a family of cell surface glycoproteins that are overexpressed in many carcinomas. CEA has been shown to function in vitro as a homotypic intercellular adhesion molecule. This correlation of overproduction of an adhesion molecule with neoplastic transformation provoked a test of the effect of CEA on cell differentiation. Using stable CEA transfectants of the rat L6 myoblast cell line as a model system of differentiation, we show that fusion into myotubes and, in fact, the entire molecular program of differentiation, including creatine phosphokinase upregulation, myogenin upregulation, and beta-actin downregulation are completely abrogated by the ectopic expression of CEA. The blocking of the upregulation of myogenin, a transcriptional regulator responsible for the execution of the entire myogenic differentiation program, indicates that CEA expression intercepts the process at a very early stage. The adhesion function of CEA is essential for this effect since an adhesion-defective N domain deletion mutant of CEA was ineffective in blocking fusion and CEA transfectants treated with adhesion-blocking peptides fused normally. Furthermore, CEA transfectants maintain their high division potential, whereas control transfectants lose division potential with differentiation similarly to the parental cell line. Thus the expression of functional CEA on the surface of cells can block terminal differentiation and maintain proliferative potential.

Adhesion to carcinoembryonic antigen by human colorectal carcinoma cells involves at least two epitopes

Carcinoembryonic antigen (CEA) may be involved in both cell-cell and cell-substrate adhesion. Our purpose was to determine whether epitopes involved in the homophilic binding of human colorectal carcinoma cells to CEA participated in adhesion to basement membrane proteins. Three human colorectal adenocarcinoma cell lines and one CHO cell line transfected with CEA cDNA were tested in a solid-phase adhesion assay. The 2 CEA-expressing carcinoma cell lines (KM-12c and CCL 188) and the transfectant, but not the parental CHO line, bound to CEA. The CEA-non-producing carcinoma line (Clone A) did not bind to CEA. All colorectal carcinoma cell lines, the transfectant and the parental CHO line bound to laminin, while the colorectal carcinoma lines bound to type-IV collagen. MAbs to epitopes on CEA that cross-react with non-specific cross-reacting antigen (NCA) inhibited adhesion of CEA-expressing cells to CEA. MAbs to non-cross-reactive epitopes of CEA did not block adhesion to CEA. When the inhibitory anti-CEA antibodies were compared in a competitive radioimmunoassay, 2 distinct epitopes were identified. Epitope I is in the N-terminal domain and defined by MAbs MN3, T84.1 and C110, whereas epitope II is located in the repeating loop domains and is recognized by antibodies MN15, PR3B10 and NP1. None of the antibodies to epitope I or II blocked adhesion by KM-12c or CCL 188 cells to laminin or type-IV collagen. Thus, at least 2 different regions on CEA participate in adhesion to CEA but not to collagen or laminin by CEA-expressing human colorectal carcinoma cells.

Specificity of anti-carcinoembryonic antigen monoclonal antibodies and their effects on CEA-mediated adhesion

The carcinoembryonic antigen (CEA) domain specificities of a library of monoclonal anti-CEA antibodies were determined to investigate the mechanisms of homophilic binding involved in CEA-mediated intercellular adhesion. Using an indirect immunofluorescence cell surface staining technique, the reactivities of these antibodies were tested systematically on Chinese hamster ovary cells stably transfected with constructs of CEA gene family members CEA, nonspecific cross-reacting antigen, CGM6, and biliary glycoprotein, as well as on stable Chinese hamster ovary transfectants expressing truncated CEA and CEA/nerve cell adhesion molecule chimeric proteins. Epitopes for these antibodies were thus localized on the CEA molecule as follows: monoclonal antibody groups 1, 2, and 6 react with epitopes in the N-terminal domain of CEA, whereas groups 3, 5a, 5b, and 9 react with determinants found in the internal repeating domains located in the C-terminal part of the CEA molecule. Groups 4 and 8 appear to react with a repeating epitope in the internal domains of CEA and in all CEA subfamily members. Fab fragments of monoclonal antibody group 1 block aggregation of CEA transfectant cells, indicating that a region in the N domain is involved in CEA homophilic interaction. Fab fragments of monoclonal antibody group 9 recognize an epitope dependent on the B2 and A3 domains and stimulate aggregation. These results support the recently reported CEA-CEA homophilic reciprocal binding model in which anti-parallel molecules are bound by 2 bonds between the N domain of one molecule and the A3B3 domain of the interacting partner.

Homophilic adhesion between Ig superfamily carcinoembryonic antigen molecules involves double reciprocal bonds

Both carcinoembryonic antigen (CEA) and neural cell adhesion molecule (NCAM) belong to the immunoglobulin supergene family and have been demonstrated to function as homotypic Ca(++)-independent intercellular adhesion molecules. CEA and NCAM cannot associate heterotypically indicating that they have different binding specificities. To define the domains of CEA involved in homotypic interaction, hybrid cDNAs consisting of various domains from CEA and NCAM were constructed and were transfected into a CHO-derived cell line; stable transfectant clones showing cell surface expression of CEA/NCAM chimeric-proteins were assessed for their adhesive properties by homotypic and heterotypic aggregation assays. The results indicate that all five of the Ig(C)-like domains of NCAM are required for intercellular adhesion while the COOH-terminal domain containing the fibronectin-like repeats is dispensable. The results also show that adhesion mediated by CEA involves binding between the Ig(V)-like amino-terminal domain and one of the Ig(C)-like internal repeat domains: thus while transfectants expressing constructs containing either the N domain or the internal domains alone were incapable of homotypic adhesion, they formed heterotypic aggregates when mixed. Furthermore, peptides consisting of both the N domain and the third internal repeat domain of CEA blocked CEA-mediated cell aggregation, thus providing direct evidence for the involvement of the two domains in adhesion. We therefore propose a novel model for interactions between immunoglobulin supergene family members in which especially strong binding is effected by double reciprocal interactions between the V-like domains and C-like domains of antiparallel CEA molecules on apposing cell surfaces.

Kohlschütter-Tönz syndrome: epilepsy, dementia, and amelogenesis imperfecta

Kohlschütter-Tönz syndrome is a central nervous system (CNS) degenerative disease with convulsions and mental regression in which the affected children present with yellow teeth due to defective enamel. We present a family in which 2 affected children (a boy and a girl) were born to consanguineous parents. This report confirms the autosomal recessive inheritance of the disorder. The combination of a CNS and an enamel defect may represent pleiotropy or a contiguous gene syndrome.

Polygenic nature of spontaneous diabetes in the rat. Permissive MHC haplotype and presence of the lymphopenic trait of the BB rat are not sufficient to produce susceptibility

We describe the phenotypic characteristics of animals in the fifth backcross-intercross generation of a breeding program in which the RT1 u haplotype and the phenotypic trait responsible for the T-lymphopenia of BB rats have been transferred to the ACI background. In this generation of animals, 24% were lymphopenic with decreased numbers of PBL expressing CD5, TCR alpha, and RT6. The PBL of the lymphopenic animals had a decreased mitogenic response to ConA. All of the nonlymphopenic animals were homozygous for RT6.2. Phenotypic analysis of intestinal IEL revealed that this was also the case for the lymphopenic animals. Moreover, IEL of the lymphopenic animals exhibited a pattern of staining (increased numbers of TCR alpha beta+CD4+CD8+ and decreased numbers of TCR alpha beta+CD4-CD8+) similar to that of BB DP animals. The ACI.1U(BB)-lymphopenic animals, although having two of the genetic traits associated with the expression of spontaneous diabetes mellitus, uniformly fail to develop diabetes. Breeding studies in which these animals were crossed with BB and hBB rats suggest that other genes are necessary for development of overt diabetes.

Marginal leakage of class II glass ionomer-composite resin restorations: an in vitro study

This in vitro study assessed the sealing properties of two metal-reinforced glass ionomer cements, used as "extended bases" in glass ionomer-composite resin restorations. Two class II cavities were prepared in the proximal surfaces of 30 molars. The gingival margin of one was prepared in enamel and the other in cementum/dentin. Fifteen teeth (30 cavities) were restored with Ketac Silver material used as an extended base (group A). In the remaining 15 teeth (30 cavities), the extended base was in Miracle Mix material (group B). All occlusal surfaces were restored with Estilux Posterior Material. The restored teeth were thermocycled, immersed in fuchsin, washed in water, embedded, sectioned, and examined under a dissecting microscope. All restorations with margins in cementum/dentin of group A (Ketac Silver) leaked. No microleakage occurred in 12 of the 30 restorations with margins in cementum/dentin of group B (Miracle Mix). In addition, severe microleakage was present in 24 teeth of group A, as opposed to three in group B. It was concluded that the sealing properties of Miracle Mix material are superior to those of Ketac Silver material, in vitro.

Marginal leakage around V-shaped cavities restored with glass-ionomer cements: an in vitro study

The object of this investigation was to assess the degree of marginal leakage around V-shaped cervical glass-ionomer cement restorations and compare it to that around composite resin restorations. Three different glass-ionomer cements and one composite resin control were assessed by means of dye penetration. Severe microleakage at the occlusal margins was found in 70% of the glass-ionomer cement restorations, but in only 10% of the composite resin restorations. A considerable amount of dye penetration was observed at the cervical margins of all restorations, including the controls. None of the glass-ionomer cements tested showed superiority in preventing marginal leakage occlusally or gingivally.

Biliary glycoprotein, a member of the immunoglobulin supergene family, functions in vitro as a Ca2(+)-dependent intercellular adhesion molecule

Intercellular adhesion molecules can be classified as Ca2+ dependent or Ca2+ independent. This classification has significant functional implications regarding cellular interactions. The best characterized Ca2(+)-dependent adhesion molecules, such as L-CAM or E-cadherin, belong to the family of closely related cell surface molecules called cadherins. On the other hand, those immunoglobulin supergene family members which function as adhesion molecules, such as neural cell adhesion molecule, have been found to be Ca2+ independent. In agreement with this generalization, we have recently shown that carcinoembryonic antigen (CEA) and nonspecific cross-reacting antigen (NCA), two closely related members of the CEA family, a subset of the immunoglobulin supergene family, function in vitro as Ca2(+)-independent adhesion molecules. In contrast, we show here that transfectants of a third member of the CEA family, biliary glycoprotein (BGP), also aggregate homotypically in suspension but require Ca2+ for aggregation. In addition, like the cadherins and unlike CEA or NCA or other adhesion molecules of the immunoglobulin supergene family, BGP transfectant aggregation requires physiological temperatures. Two forms of BGP, with three and two immunoglobulin C2-set domains, show Ca2(+)- and temperature-dependent adhesion, so that these properties do not reside in the third C2-set domain. The significance of this expression in the range of functional properties of the immunoglobulin supergene family and its CEA subset is discussed.

Monoclonal anti-CEA antibodies in the discrimination between primary pulmonary adenocarcinoma and colon carcinoma metastatic to the lung

Lung metastases from colon adenocarcinoma are often difficult to differentiate from primary lung adenocarcinoma. We studied the diagnostic value of a polyclonal anti-CEA antiserum and two monoclonal anti-CEA antibodies (B18, D14) which define antigens overexpressed in colon carcinoma. Autopsy material from 20 patients with colon carcinoma and lung metastases and 20 specimens from patients with primary lung adenocarcinoma were retrieved, stained, and interpreted without knowledge of the origin of the lung tumor. Colon carcinomas, lung metastases and lung primaries stained positively with polyclonal anti-CEA in 90-100% of cases. D14 stained 75% of colonic metastases and 70% of primary lung adenocarcinomas, whereas 95% of colon primaries were positive. Sixty-five percent of colon primaries and 50% of their metastases were positive with B18, whereas 45% of lung primaries were positive. The frequency of B18 positivity was significantly greater in those colon primaries that were surgically derived (7/9, 78%) compared with their autopsy-derived lung metastases (2/9, 22%) (P less than 0.05). Similarly, D14 staining in surgically derived colon primaries (9/9, 100%) was significantly greater than their autopsy-derived lung metastases (5/9, 56%) (P less than 0.05). In surgical/biopsy-derived tissues 9/9 colonic primaries were D14-positive, whereas only 1 of 6 lung primaries was positive (P = 0.002). We conclude that D14 and polyclonal anti-CEA both stain the majority of colon adenocarcinomas and that changes associated with prolonged fixation may reduce the positivity rate with both B18 and D14 monoclonal antibodies. All three antibodies stain autopsy-derived tissue from primary lung cancer to a significant degree.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative clinical study of autopolymerized and light-polymerized fissure sealants: five-year results

The retention of autopolymerized and light-polymerized Delton fissure sealants was compared. Sealants were applied to 207 first permanent molars with 304 separate sites in 73 children 6-8 years old (mean age 6.3 years). After five years, there was complete retention in 59% of the autopolymerized and 48% of the light-polymerized sealants. The resulting 11% difference in retention rates was not statistically significant at P less than 0.05.

Specificity of intercellular adhesion mediated by various members of the immunoglobulin supergene family

The immunoglobulin supergene family members have been shown to be involved in cell-cell recognition and interaction during cell growth and differentiation. Neural cell adhesion molecule, myelin-associated glycoprotein, and carcinoembryonic antigen (CEA) are immunoglobulin supergene family members which can mediate cell adhesion. We show here that nonspecific cross-reacting antigen (NCA), a closely related CEA family member, is found on the surface of rodent cells transfected with functional NCA complementary DNA in different glycosylated forms, all of which can be deglycosylated to an Mr 35,000 core protein. Furthermore, NCA can mediate Ca2(+)-independent, homotypic aggregation of these NCA-producing transfectant cells. Since CEA has three internal repeated C2-set, immunoglobulin-like domains, whereas NCA has one, only one such domain is required for the intercellular adhesive function. We also demonstrate that NCA- and CEA-producing transfectants can form heterotypic aggregates, whereas mixtures of CEA or NCA transfectants and neural cell adhesion molecule or long form-myelin-associated glycoprotein transfectants sort themselves out into homotypic aggregates. The results suggest that subsets of the immunoglobulin superfamily, such as the CEA family, can be used in both homotypic and heterotypic cellular interactions, whereas less closely related members of the family can be used to separate different cell types by strictly homotypic interactions.

Interferon-gamma induces transcription and differential expression of MHC genes in rat insulinoma cell line RINm5F

We have reported that enhanced levels of class I major histocompatibility complex (MHC) antigen are expressed throughout the islets of prediabetic and newly diabetic BB rats and that the endocrine cells of the islet remained class II negative. In this study we investigated the molecular biology of lymphokine-induced expression of the class I and II MHC genes in subclones of the rat insulinoma cell line RINm5F. Treatment of a particular subclone of RINm5F cells (which are normally class II negative, class I low expressors) with crude lymphokine preparation or various doses of recombinant interferon-gamma resulted in enhancement of MHC class I antigen expression but no detectable induction of class II antigen expression. This enhancement of class I antigen expression was a dose-dependent phenomenon and was preceded by a dose-dependent increase in class I-specific RNA. Both class I and II genes were induced at the transcriptional level, as determined by Northern blotting and in vitro nuclear transcription assays, but exhibited strikingly different induction kinetics. Supernatants from concanavalin A-stimulated splenocytes had a similar class I-restricted inductive effect on MHC gene expression. This subclone of RINm5F cells, which exhibits a class I lymphokine response-positive, class II response-negative phenotype, 1) mimics the behavior of beta-cells in the prediabetic and newly diabetic pancreas and 2) represents a valuable system for probing the similarities and differences in the lymphokine-mediated induction pathways for class I and II MHC genes.

Carcinoembryonic antigen, a human tumor marker, functions as an intercellular adhesion molecule

Carcinoembryonic antigen (CEA) is a member of a family of cell surface glycoproteins that are produced in excess in essentially all human colon carcinomas and in a high proportion of carcinomas at many other sites. The function of this widely used tumor marker and its relevance to malignant transformation is therefore of considerable interest. We demonstrate here that CEA mediates Ca2+-independent, homotypic aggregation of cultured human colon adenocarcinoma cells (LS-180) and rodent cells transfected with functional CEA cDNA. Furthermore, CEA can effect the homotypic sorting of cells in heterogeneous populations of aggregating cells. CEA can thus be considered a new addition to the family of intercellular adhesion molecules. We also show that, whereas CEA is localized mainly to epithelial cell membranes facing the lumen in normal adult intestine, it is found on adjacent cell membranes in both embryonic intestine and colonic tumors. A model for the role of CEA in the tissue architecture of adult, embryonic, and aberrant tumor intestinal epithelium is presented.

A mouse analogue of the human carcinoembryonic antigen

Functional human carcinoembryonic antigen (CEA)-like genes have been shown to be present in the mouse. Southern analyses of murine DNA using both human and murine CEA complementary DNA probes have revealed the presence of multiple CEA-like genes, while analyses of RNA from different mouse tissues showed CEA-like transcripts in adult colon and liver. Furthermore, a CEA-like protein, immunoprecipitable with a rabbit polyclonal serum raised against human CEA, has been detected in adult murine colon tissue. Several murine CEA complementary DNA clones have been isolated from a murine colon complementary DNA library, and characterization of one such clone demonstrates that both the N-terminal and the internal domains have been conserved between the two species. The existence of a murine counterpart of CEA strengthens the case for an essential function for this human tumor marker and provides an experimentally amenable system for elucidation of its biological properties.

Studies on the control of gene expression of the carcinoembryonic antigen family in human tissue

The control of expression of genes of the carcinoembryonic antigen family was investigated in 22 specimens of malignant and nonmalignant human colonic tissues. These surgical specimens included seven colonic adenocarcinomas that were compared with normal adjacent colonic mucosal tissues from the same individual. mRNA preparations from all colonic tissues expressed three bands of 3.5, 3.0, and 2.6 kilobases on Northern blots probed with carcinoembryonic antigen (CEA) complementary DNA probe while normal liver and spleen were negative. The major band of 3.0 kilobases was 6 to 10 times more intense in the colon tumor specimens than in the matched normal mucosa. However, the tumor/normal ratios of immunoreactive CEA in these pairs varied from 2- to greater than 100-fold. Furthermore, there was no direct proportionality between mRNA levels and gene product expression, suggesting that the known variations in CEA expression in human colonic tissues result from both transcriptional and posttranscriptional control mechanisms. Southern blots of DNA from these specimens did not reveal any gene rearrangements or amplifications accompanying expression. Finally, Southern blots of DNA digested with methylation-sensitive endonucleases and probed with a genomic DNA fragment upstream of CEA gene coding regions demonstrated that CEA expression is correlated with a decreased level of methylation in the 5' region of the CEA gene.

IDDM in BB rats. Enhanced MHC class I heavy-chain gene expression in pancreatic islets

Modulation in major histocompatibility complex (MHC) gene expression correlates with the inflammatory reactions that occur during graft rejection and autoimmune disease. We analyzed the expression of class I and II MHC genes in the pancreatic islets of prediabetic and newly diabetic BB rats by immunohistochemistry of tissue sections and Northern blotting of RNA extracted from isolated islets. We show that enhanced levels of MHC class I heavy-chain RNA are present in pancreatic islets before overt inflammation and the onset of insulin-dependent diabetes mellitus (IDDM) in the spontaneously diabetic BB rat. Immunohistochemical analysis revealed enhanced class I antigen expression throughout the pancreatic islets of newly diabetic animals but no induction of class II antigen on endocrine cells within the islet. Varying degrees of inflammatory infiltrate were observed in the sections exhibiting enhanced class I antigen expression or in nearby serial sections. Southern blot analysis revealed no restriction-fragment-length polymorphism or amplification of the endogenous class I heavy-chain genes compared with those of seroidentical disease-resistant Wistar-Furth rats. I-A alpha and I-E alpha hybridizing RNA appeared de novo before overt diabetes, although concomitantly with T-lymphocyte-receptor beta-chain and interferon-gamma gene hybridizing RNA and after MHC class I heavy-chain RNA enhancement was observed. These data indicate the possibility that enhanced class I heavy-chain gene expression plays a role in the progression of IDDM.

Association of susceptibility to spontaneous diabetes in rat with genes of major histocompatibility complex

This study was designed to map the diabetes susceptibility gene(s) associated with the rat major histocompatibility complex (MHC) RT1. We have crossed spontaneously diabetic male rats bearing the recombinant RT1r8 haplotype with female rats of the AC1.1r4 congenic strain. Three diabetic rats were determined to be homozygous for the r4 haplotype by serotyping. The absence of recombination within the MHC was confirmed by inspection of restriction-fragment-length patterns of the diabetic animals and the parental strains. In conjunction with previous breeding studies, this study maps the diabetes susceptibility gene to the right of the RT1-A locus and to the left of the RT1-C locus. A low incidence of diabetes in the F2 (4.5%) emphasizes the multifactorial nature of the susceptibility. The presence of depressed responsiveness of peripheral blood lymphocytes to concanavalin A stimulation increases the prevalence of the overt disease. An unusual feature of the diabetic syndrome in this study is the sparse or absent pancreatic lymphocytic inflammatory response, with true insulitis being a rare finding.

Transcription of genes of the carcinoembryonic antigen family in malignant and nonmalignant human tissues

Normal and diseased human tissues were analyzed for the transcription of genes of the carcinoembryonic (CEA) family. Epithelial tissues of colonic origin, whether malignant or normal, all express two closely related mRNA species of 3.0- and 3.5-kilobase mRNA which code for CEA. Only tissues of colonic origin were found to express these CEA-specific transcripts. Colon carcinomas consistently express a 2.6-kilobase mRNA species as well which codes for nonspecific cross-reacting antigen. Nonneoplastic colon mucosas, on the other hand, express lower or nondetectable levels of this transcript. Most breast carcinomas produce only the nonspecific cross-reacting antigen mRNA, whereas leukocytes of chronic myelogeneous leukemia express both nonspecific cross-reacting antigen mRNA and a 2.3-kilobase mRNA corresponding to a yet undefined gene of the CEA family. Thus the multiple CEA-like products reported to be produced by these tissues correspond to only four different mRNA species coding for three different peptides. These data suggest a less complex organization of the CEA family than was previously suspected and point to posttranscriptional modifications, such as variable patterns of glycosylation, as the likely reason for much of the observed complexity in CEA-like glycoproteins.

Effect of trauma to the primary incisors on the alignment of their permanent successors in Israelis

117 children who had experienced trauma to their primary incisors were re-examined in their transitional or permanent dentition stage. The control group consisted of 174 children with a corresponding dental developmental age. All the children were examined clinically and the intra- and interarch relations of the anterior segments were recorded. The prevalence of patients with at least one malposed incisor was higher in the trauma group. Trauma to the primary dentition was found to be a contributing factor affecting the alignment of the permanent successors. Early loss of the primary incisors did not cause loss of space in most of the cases; however, it was associated with malposition of their permanent successors. Lack of eruption guidance or the direct effect of the injury on the position of the developing bud could be considered as contributing etiologic factors. There was a very low prevalence of more serious malocclusion features, like impaction, in the trauma group.

The effect of VLC Scotchbond and an incremental filling technique on leakage around Class II composite restorations

The object of this study was to determine the effect of VLC Scotchbond and of an incremental filling technique on microleakage around class II composite restoration in vitro. Four groups of 15-16 teeth each, were filled with the resin P-30 by one of the following techniques: A, Scotchbond and incremental filling; B, Scotchbond and bulk filling; C, Enamel Bond and incremental filling; D, Enamel Bond and bulk filling. The teeth were thermocycled, insulated up to 1 mm from the restorations, immersed in 2 percent basic fuchsin, embedded in acrylic resin and ground off to various depths, parallel to the plane through the vertical and the mesiodistal axes. Marginal leakage was assessed from the degree of dye penetration at the sections. Dye penetration at the occlusal margins was similar for all groups. Dye penetration at the cervical margins for the different groups increased in the sequence: A/C/B/D. Incremental filling resulted in a significantly lower dye penetration at cervical margins for both bonding agents. The differences resulting from the use of Scotchbond were not significant, if the same packing technique had been used. Best results were obtained with Scotchbond and incremental filling.