Interval Colorectal Cancers: What and Why

An increasing number of studies now indicate that colonoscopic examination is not perfect in preventing colorectal cancer (CRC), especially of the proximal colon. Several factors can be implicated in the occurrence of interval CRCs—further referred to as postcolonoscopy CRCs-, such as missed, incompletely resected lesions and newly developed cancers. Missed lesions represent by far the dominant cause of postcolonoscopy CRCs, with nonpolypoid (flat or depressed) neoplasms and sessile serrated polyps playing a significant role. Molecular events underlying progression of such lesions may further augment the cancer risk. In this article, we review the literature about postcolonoscopy CRC risk and the most common explanations. We discuss potential implications, paying special attention to improvements required in education and training.     

Rheologic predictors of the severity of the painful sickle cell crisis

Deformable sickle erythrocytes have been reported by Mohandas and Evans to be more adherent to vascular endothelium than rigid irreversibly sickled cells (ISC). To define the clinical implications of this finding we have determined genetic, hematological, clinical, and rheological characteristics of sickle erythrocytes obtained from 65 patients with sickle cell anemia and fetal hemoglobin (Hb F) levels less than 15%. The alpha-globin gene number had a significant effect on the hematological parameters, the percentage of dense cells, ISC number, and HB A2 levels. The presence or absence of alpha thalassemia, however, had no effect on the frequency and severity of the sickle cell painful crisis (r = 0.06, P greater than .05). RBC deformability, determined by an ektacytometer, showed great heterogeneity among patients with three or four alpha-globin genes. Linear regression analyses of the data showed significant positive correlation of the frequency and severity of the painful crisis with RBC deformability (r = 0.49, P less than .001), and negative correlations with the percentage of dense cells (r = -0.37, P = .002), and the percentage of ISC (r = -0.46, P less than .001). We propose that the more deformable the sickle RBC are, the greater their adherence to vascular endothelium, and the more they cause vaso-occlusive crises, RBC deformability and the percentage of dense cells (or ISC) seem to have a predictive value of the frequency and severity of painful crises in sickle cell anemia.     

Human cytomegalovirus increases constitutive production of interleukin- 6 and leukemia inhibitory factor by bone marrow stromal cells

Human cytomegalovirus (CMV) infection is often associated with myelosuppression and acute inflammatory reaction in immunocompromised patients. We have previously documented that CMV exposure of bone marrow (BM) stromal cells reduces the capacity of these cells to support hematopoiesis because of a decreased production of colony- stimulating factors. This study examines the potential role of CMV on constitutive and lipopolysaccharide (LPS)-stimulated production of cytokines involved in inflammatory reaction, interleukin-6 (IL-6) and leukemia inhibitory factor (LIF) by BM stromal cells. The release of IL- 6 was already detectable 2 hours post CMV-infection (2.5-fold increase in production) and the cumulative production of IL-6 after 5 days of infection was 23 +/- 1.2 ng/mL (ninefold increase in production). CMV was also able to induce a time-dependent production of LIF that was maximal 8 hours after CMV infection (2.5-fold increase in production). Concomitantly, there was no detectable release of granulocyte colony- stimulating factor (G-CSF) and granulocyte-macrophage CSF (GM-CSF) by CMV-infected stromal cells. The similar IL-6 and LIF production in the presence of polymyxin B ruled out the possibility that this increase could be caused by contamination of the viral stock by endotoxin. In addition, ultraviolet-inactivated virus behaved similarly to live virus and caused the release of IL-6 and LIF. However, heat-inactivated CMV was unable to induce IL-6 and LIF secretion by BM stromal cells. The production of IL-6 and LIF was also evaluated after stimulation by LPS. After 5 days of CMV exposure, the LPS-stimulated production of IL-6 and LIF was significantly lower than uninfected controls. This LPS-induced release of cytokine production was found to be dependent of viral replication. The experiments have shown that CMV is a potent inducer of IL-6 and LIF with differential effect on constitutive and LPS- stimulated cytokine production by stromal cells; we suggest that CMV induction of IL-6 and LIF during the first hours of infection could play a role in CMV-induced inflammatory reaction. Moreover, our results show that human CMV can disturb the balanced cytokine network involved in the regulation of hematopoiesis.     

Sustained, retransplantable, multilineage engraftment of highly purified adult human bone marrow stem cells in vivo

Data from many laboratory and clinical investigations indicate that CD34+ cells comprise approximately 1% of human bone marrow (BM) mononuclear cells, including the progenitor cells of all the lymphohematopoietic lineages and lymphohematopoietic stem cells (stem cells). Because stem cells are an important but rare cell type in the CD34+ cell population, investigators have subdivided the CD34+ cell population to further enrich stem cells. The CD34+/CD38- cell subset comprises less than 10% of human CD34+ adult BM cells (equivalent to < 0.1% of marrow mononuclear cells), lacks lineage (lin) antigens, contains cells with in vitro replating capacity, and is predicted to be highly enriched for stem cells. The present investigation tested whether the CD34+/CD38- subset of adult human marrow generates human hematopoiesis after transfer to preimmune fetal sheep. CD34+/ CD38- cells purified from marrow using immunomagnetic microspheres or fluorescence-activated cell sorting generated easily detectable, long- term, multilineage human hematopoiesis in the human-fetal sheep in vivo model. In contrast, transfer of CD34+/CD38+ cells to preimmune fetal sheep generated only short-term human hematopoiesis, possibly suggesting that the CD34+/CD38+ cell population contains relatively early multipotent hematopoletic progenitor cells, but not stem cells. This work extends the prior in vitro evidence that the earliest cells in fetal and adult human marrow lack CD38 expression. In summary, the CD34+/ CD38- cell population has a high capacity for long-term multilineage hematopoietic engraftment, suggesting the presence of stem cells in this minor adult human marrow cell subset.     

Liver-derived fetal hematopoietic stem cells selectively and preferentially home to the fetal bone marrow

In the course of ontogeny, the homing site for the hematopoietic stem cells (HSC) moves with certain predictability from the yolk sac to the liver/spleen and then to the marrow. The pattern of this migration has thus far been established mostly on a morphologic basis. To delineate further the course of this migration and to gain insight into its possible mechanism, we used in utero transplantation of allogeneic or xenogeneic HSC in preimmune sheep fetuses. Sex chromosome, type of hemoglobin, and species-specific surface markers were used to follow the path of transplanted cells in the fetus. Before the development of the bone marrow, transplanted HSC (liver- or marrow-derived) homed exclusively to the liver/spleen. With the development of marrow, around day 60 of gestation (term, 145 days), homing occurred also in the nascent marrow and by day 80 transplanted cells homed exclusively to the marrow. This suggests that there may be a hierarchy in homing sites, with those of the marrow having higher affinity than those of liver/spleen. Interestingly, despite a change in homing that was followed by the expansion of the marrow compartment of HSC (ie, HSC proliferation), these cells did not participate actively in blood cell formation during most of the prenatal period. Liver remained the major hematopoietic organ throughout the gestation. It was only during the perinatal period that this organ assumed the function of hematopoiesis from the liver. This lack of expression of HSC in fetal marrow can possibly be attributable to the immaturity of marrow stroma required for differentiation and maturation of progenitors and the orderly egress of mature cells into the blood stream. The availability of this model allows us to begin studies in the molecular mechanism of stem cell homing in vivo during ontogeny.     

Recurrence of aplastic anemia following cyclophosphamide and syngeneic bone marrow transplantation: evidence for two mechanisms of graft failure

Two patients with aplastic anemia were treated with high-dose cyclophosphamide and marrow transplantation from their normal, genetically identical twin. Both patients rapidly recovered normal marrow function, but marrow failure recurred 13 and 18 months later. Because donor and host pairs were identical twins, these cases of graft failure could not have resulted from the usual cause of graft failure, ie, immunological reactivity of host cells against unshared minor histocompatibility antigens of the donor. These results imply that there are at least two mechanisms responsible for graft failure after marrow transplantation for severe aplastic anemia.     

Presentation of a cone-beam CT scanning protocol for preprosthetic cranial bone grafting of the atrophic maxilla

The use of autologous calvarian split thickness bone grafts is a well accepted preprosthetic surgical procedure for reconstruction of the severely atrophied maxilla. Although generally accepted as being a superior bone graft regarding long-term stability, the reported risks in the literature may dissuade the surgeon. A modified cone-beam computed tomography (CBCT) scanning protocol (extended field of view starting from 1cm below the occlusal plane up to the limit of the cranial vault, 0.4 voxel) is proposed that allows assessment of both the cranial donor site as the maxillary receptor site and the sinus conditions with a single scan. Issues regarding quality of the data, radiation dose and clinical practicability are discussed.     

Halitosis and oral health-related quality of life: a case report

To cite this article:
Int J Dent Hygiene 10 , 2012; 3–8
DOI: 10.1111/j.1601‐5037.2011.00512.x
Buunk‐Werkhoven YAB, Dijkstra‐le Clercq M, Verheggen‐Udding EL, de Jong N, Spreen M. Halitosis and oral health‐related quality of life: a case report. Abstract: Objectives: This is a clinical case of a 36‐year‐old Dutch male, patient in the Dr. S. van Mesdag Forensic Psychiatric Centre in Groningen. It demonstrates a short‐time effect of a tailored oral hygiene self‐care intervention in three sessions over a period of 3 months on halitosis and a patient’s oral health‐related quality of life (OH‐QoL). Methods: In addition to a dental screening and professional oral hygiene care, a semi‐structured interview was conducted by the dental hygienist, and questionnaires were administered. The questionnaires included were; the Dutch version of the Oral Health Impact Profile‐14 (OHIP‐14‐NL; used as a measurement of OH‐QoL), scales for expected social outcomes for having healthy teeth, attitudes towards oral hygiene behaviour (OHB) and dental anxiety. Results: Clinical observations showed an improvement in patient’s OHB, while the extreme foetor‐ex‐ore was reduced to an acceptable level. A retrospective assessment showed that patient’s attitude towards the recommended OHB together with his self‐perceived OH‐QoL had positively increased. Conclusions: This case highlights the value of professional individual oral hygiene instructions performed by a dental hygienist. It also illustrates that a patient’s effective OHB may play an important role in the reduction in halitosis and self‐perceived OH‐QoL. Finally, the retrospective version of the OHIP‐14‐NL may be an adequate method to assess self‐perceived OH‐QoL within a relative short period of time.     

Long‐Term Clinical,Microbiological, and Radiographic Outcomes of Brånemark™ Implants Installed in Augmented Maxillary Bone for Fixed Full‐Arch Rehabilitation

Purpose: The purpose of this study was to document the long‐term outcome of Brånemark implants installed in augmented maxillary bone and to identify parameters that are associated with peri‐implant bone level. Material and Methods: Patients of a periodontal practice who had been referred to a maxillofacial surgeon for iliac crest bone grafting in the atrophic maxilla were retrospectively recruited. Five months following grafting, they received 7–8 turned Brånemark implants. Following submerged healing of another 5 months, implants were uncovered and restorative procedures for fixed rehabilitation were initiated 2–3 months thereafter. The primary outcome variable was bone level defined as the distance from the implant‐abutment interface to the first visible bone‐to‐implant contact. Secondary outcome variables included plaque index, bleeding index, probing depth, and levels of 40 species in subgingival plaque samples as identified by means of checkerboard DNA–DNA hybridization. Results: Nine out of 16 patients (eight females, one male; mean age 59) with 71 implants agreed to come in for evaluation after on average 9 years (SD 4; range 3–13) of function. One implant was deemed mobile at the time of inspection. Clinical conditions were acceptable with 11% of the implants showing pockets ≥ 5 mm. Periodontopathogens were encountered frequently and in high numbers. Clinical parameters and bacterial levels were highly patient dependent. The mean bone level was 2.30 mm (SD 1.53; range 0.00–6.95), with 23% of the implants demonstrating advanced resorption (bone level > 3 mm). Regression analysis showed a significant association of the patient (p < .001) and plaque index (p = .007) with bone level. Conclusions: The long‐term outcome of Brånemark implants installed in iliac crest‐augmented maxillary bone is acceptable; however, advanced peri‐implant bone loss is rather common and indicative of graft resorption. This phenomenon is patient dependent and seems also associated with oral hygiene.     

Startling secrets: startle eye blink modulation by concealed crime information

We used the startle eye blink paradigm to investigate the processes underlying physiological responding to concealed information. Autonomic responding was measured together with eye blink responses to startle probes presented during mock crime and control pictures. Based upon 'orienting theory', greater startle modulation to crime pictures in comparison to control pictures was expected. The electrodermal, heart rate and respiratory changes in Experiment 1 (n=29) showed enhanced orienting to the crime pictures, but we observed reduced rather than enhanced startle modulation. In Experiment 2 (n=91) and Experiment 3 (n=38), participants either were or were not instructed to inhibit physiological responding in order to test whether inhibition was an explanation for the pattern of startle blink responding. Reduced startle modulation was observed only when participants inhibited physiological responding, confirming the proposed role of inhibition. The data suggest that not only orienting, but also inhibition contributes to physiological responding to concealed information.