Clinical utility of molecular and flow cytometric markers in chronic lymphocytic leukaemia.

BACKGROUND: Chronic lymphocytic leukaemia (CLL) is a clinically heterogeneous disease. While immunoglobulin variable region heavy chain (IgVH) mutational status remains the 'gold standard' in molecular prognostication, a range of additional markers is increasingly being used in clinical trials. As awareness of trial data increases, requests to determine these prognostic markers for new CLL patients are becoming more prevalent in Australia. AIM: To explore the clinical utility of currently available prognostic markers for CLL in an Australian cohort. METHODS: IgVH mutational status and gene usage was determined and compared with other reported immunophenotypic markers, cytogenetics and clinical outcome as defined by treatment-free survival (TFS), lymphocyte doubling time and clinical stage in a cohort of 65 CLL patients. RESULTS: An unmutated IgVH gene, high expression of CD38, ZAP-70, CD25, CD49d, CD54 or low expression of CD49c was associated with shorter TFS indicating an adverse clinical prognosis in our cohort. High expression of each of CD38, ZAP-70, CD49d and CD54 was significantly associated with an unmutated IgVH gene; however, associations were not absolute. IgVH and CD25 expression retained their significance in multivariate analysis. Concordant CD25(high) /IgVH unmutated CLL patients had the shortest median TFS interval (40 months) in our cohort. CONCLUSIONS: Molecular and immunophenotypic markers remain useful as adjuncts to clinical prognostication; however, as single parameters they are unable to dictate the timing of therapeutic intervention. The combined use of CD25 and IgVH mutational status may be clinically relevant to CLL prognostication while also providing insight into the biological pathways involved in disease progression.

Transcription factor IIIA gene expression in Xenopus oocytes utilizes a transcription factor similar to the major late transcription factor.

Xenopus transcription factor IIIA (TFIIIA) gene expression is stringently regulated during development. The steady-state level of TFIIIA mRNA in a somatic cell is approximately 10(6) times less than in an immature oocyte. We have undertaken studies designed to identify differences in how the TFIIIA gene is transcribed in oocytes and somatic cells. In this regard, we have localized an upstream transcriptional control element in the TFIIIA promoter that stimulates transcription from the TFIIIA promoter approximately threefold in microinjected oocytes. The upstream element, in cis. does not stimulate transcription from the TFIIIA promoter in somatic cells. Thus, the element appears to be oocyte specific in the context of the TFIIIA promoter. However, both oocytes and somatic cells contain a protein (or a related protein) that binds the upstream element. We have termed this protein from oocytes the TFIIIA distal element factor. The sequence of the upstream element is similar to the sequence of the upstream element found in the adenovirus major late promoter that is a binding site for the major late transcription factor. By gel shift analysis, chemical footprinting, methylation intereference, and point mutation analysis, we demonstrate that the TFIIIA distal element factor and major late transcription factor have similar DNA-binding properties.

Activation of the phosphoenolpyruvate carboxykinase gene retinoic acid response element is dependent on a retinoic acid receptor/coregulator complex.

The accessory factor 1 (AF1) element is an upstream transcriptional control region that plays a role in the response of the phosphoenolpyruvate carboxykinase (PEPCK) gene to both glucocorticoids and retinoic acid. We demonstrate here that retinoic acid receptor alpha (RAR alpha) binds to a sequence within the AF1 element, TGACCT (site B), that is a consensus retinoic acid response element (RARE) half-site. A similar DNA sequence, TGGCCG (site C), located 1 bp downstream of site B, is not involved in the binding of RAR alpha monomers or dimers but is required for the constitution of a functional RARE. Site C is also required for the formation of a complex involving RAR alpha and a liver nuclear factor designated CR, for coregulator. Mutational analysis of the AF1 element shows that the RAR alpha/CR complex is the trans-acting unit that mediates the retinoic acid response of the PEPCK gene. Another member of the retinoid receptor family, retinoid X receptor alpha (RXR alpha), can also form a complex with RAR alpha and the AF1 element. Several observations, including the observation that RXR alpha antibody interacts with CR, indicate that RXR alpha and CR are identical or closely related proteins. Through RXR alpha forms a complex with RAR alpha and the AF1 element, we demonstrate that the AF1 element is functionally distinguishable from a retinoid X response element. Taken together, our results show that the AF1 element contains an RARE that mediates a retinoic acid response by binding an RAR alpha/coregulator complex; this coregulator is presumably RXR alpha.

A carcinogenicity study of pesticide dieldrin in hamsters.

Syrian golden hamsters were fed for their lifespan a diet containing 0, 20, 60 and 180 parts per million (ppm) Dieldrin. Tumour-bearing animals totaled 13% among control females and ranged between 3-15% in treated females. Eight per cent of male controls had tumours and between 16-23% of treated males. Incidences of endocrine organ tumours were comparable in all groups. A hepatoma was found in 1 female and 1 male led 180 ppm Dieldrin. The present results show that hamsters tolerate higher doses of Dieldrin than do mice and rats. No significant tumour incidence was observed in treated versus control Syrian golden hamsters.

SHH mutation is associated with solitary median maxillary central incisor: a study of 13 patients and review of the literature.

Solitary median maxillary central incisor (SMMCI) or single central incisor is a rare dental anomaly. It has been reported in holoprosencephaly (HPE) cases with severe facial anomalies or as a microform in autosomal dominant HPE (ADHPE). In our review of the literature, we note that SMMCI may also occur as an isolated finding or in association with other systemic abnormalities. These anomalies include short stature, pituitary insufficiency, microcephaly, choanal atresia, midnasal stenosis, and congenital nasal pyriform aperture stenosis. SMMCI can also be a feature of recognized syndromes or associations or a finding in patients with specific chromosomal abnormalities. We performed a molecular study on a cohort of 13 SMMCI patients who did not have HPE. We studied two genes, Sonic Hedgehog (SHH) and SIX3, in which mutations have been reported in patients showing SMMCI as part of the HPE spectrum. A new missense mutation in SHH (I111F), segregating in one SMMCI family, was identified. Our results suggest that this mutation may be specific for the SMMCI phenotype since it has not been found in the HPE population or in normal controls. Published 2001 Wiley-Liss, Inc.

The interaction of maintenance interferon with cytolytic cells in patients with multiple myeloma who responded to cytotoxic chemotherapy.

STUDY OBJECTIVE: To determine the long-term effects of maintenance interferon on CD56+ and CD3+ cell activity. DESIGN: Prospective phase II trial. SETTING: Tertiary medical center and level 2 Veterans Administration hospital. PATIENTS: Seven patients (age 45-74 yrs) with multiple myeloma who had reached the plateau phase from cytotoxic chemotherapy, and seven age- and sex-matched controls. INTERVENTIONS: All patients were given interferon-alpha 2b 3 x 10(6) U/m2 3 times/week. MEASUREMENTS AND MAIN RESULTS: The CD56+, CD3+, and CD16+ counts were determined by flow cytometry in both peripheral blood and bone marrow. Natural killer (NK) cell functional activity was determined by a 51chromium release assay. Monocyte cell numbers were determined from the white blood cell count with differential. Interleukin-6 (IL-6) concentrations were determined by a commercially available enzyme-linked immunosorbent assay. During the 24-week study, the peripheral blood CD3+ and monocyte counts in patients with myeloma remained constant (p > or = 0.39) but their absolute CD56+ counts decreased significantly (p = 0.05). In peripheral blood, CD56+, CD16-, CD3- was the predominant phenotype in patients. The predominant phenotype in bone marrow was CD56+, CD16-, CD3+ at baseline but changed to CD56+, CD16-, CD3- by week 24. The cytolytic activity of NK cells significantly increased in bone marrow (p = 0.05) whereas it remained stable in the peripheral blood (p = 0.55), but only half that of the controls. Concentrations of IL-6 did not increase significantly during the study. CONCLUSION: In peripheral blood, NK cell activity remained stable in patients but was significantly lower than that in controls, probably secondary to the predominance of the CD56+, CD16-, CD3- phenotype in the patients. In contrast, NK cell activity increased significantly in bone marrow despite the predominance of the CD56+, CD16-, CD3- phenotype by week 24.

Mucopolysaccharidosis: MPS VI and associated delayed tooth eruption.

Eight cases of mucopolysaccharidosis Type VI (Maroteaux-Lamy syndrome) are reviewed and two cases are presented in detail. Developmental dental anomalies including unerupted and impacted permanent teeth and associated hyperplastic tooth follicles are seen frequently in MPS patients. The surgical implications and management are discussed. All patients reviewed had significant cardiovalvular disease. It is essential for the primary medical provider to establish early basic dental care and evaluation for delayed eruption of primary and permanent dentition. This will probably minimize the possibility of infective endocarditis and allow for early treatment of impacted teeth.

Lack of carcinogenicity of DDT in hamsters.

Syrian golden hamsters were fed for their lifespan a diet containing 0, 125, 250 and 500 parts per million (ppm) of ddt. The incidence of tumour bearing animals was 13% among control females and ranged between 11-20% in treated females. In control males 8% had tumours. The incidence of tumour bearing animals among treated males ranged between 17-28%. The incidence of adrenal cortex tumours showed a dose-related increase among the DDT-treated males. A liver-cell tumour and 2 liver hemangioendotheliomas were observed in 3 males treated with 250 ppm DDT. No liver-cell tumours were observed in the controls. No significant difference in tumour incidence was observed in treated versus control Syrian golden hamsters.

Effects of long-term intake of DDT on rats.

DDT is a pesticide used in malaria-control programmes throughout the world. Its potential carcinogenicity was studied in MRC Porton rats (Wistar-derived) which received dietary concentrations of 0, 125, 250 and 500 parts per million DDT (technical-grade) for life. The treatment had no adverse effects on body growth or survival rate. Various types of tumours were observed in animals in all groups: exposure to DDT resulted in statistically significant increased incidence of liver-cell tumours only in female treated rats; one such tumour was observed in control rats. No metastases of these tumours were found.

Amelogenesis imperfecta and nephrocalcinosis syndrome. Case studies of clinical features and ultrastructure of tooth enamel in two siblings.

This article describes the enamel ultrastructure and clinical features in two siblings with the little known syndrome of Amelogenesis imperfecta and nephrocalcinosis. Nephrocalcinosis was diagnosed by x-ray examination of the abdomen, intravenous pyelography, ultrasonography, and computed tomography scan. Amelogenesis imperfecta was diagnosed from clinical and histologic examinations. The affected enamel was hypoplastic (approximately 0.2 mm thick), positively birefringent, generally aprismatic, porous, and consisted of loosely packed, randomly orientated, thin (approximately 10 nm wide), ribbonlike crystals. The enamel surface was rough, extensively cracked, and covered with ovoid or globular protrusions. Observations showed that in this case hypoplasia, hypocalcification, or hypomaturation defects were present in the same tooth, indicating that both secretory and maturation phases may have been affected. The study suggested the possibility of an abnormality in interstitial matrix, which could lead to dystrophic calcification in the kidney and abnormal tooth enamel formation. It also suggested the possibility of involvement of two separate but closely linked genes.

Gingival fibromatosis and Klippel-Trénaunay-Weber syndrome. Case report.

A case of a young male with the Klippel-Trénaunay-Weber syndrome is described. Typical features of hemihypertrophy, hemangiomata, macrodactyly, and macrocephaly were present. The most striking oral feature was generalized severe gingival hypertrophy confirmed histologically, ultrastructurally, and by collagen analysis. In the absence of other known systemic causes of gingival enlargement, a diagnosis of familial gingival fibromatosis in association with Klippel-Trénaunay-Weber-syndrome is concluded. The combination of gingival fibromatosis and Klippel-Trénaunay-Weber syndrome has not been reported to our knowledge, it is uncertain whether this occurrence is significant or coincidental.

Solitary median maxillary central incisor, short stature, choanal atresia/midnasal stenosis (SMMCI) syndrome.

This article describes a series of 21 consecutive cases, each involving a solitary median maxillary central incisor; the patients were seen in the Department of Dentistry or the Victorian Clinical Genetics Unit, Murdoch Institute, at the Royal Children's Hospital, Melbourne, from 1966 to 1997. The spectrum of anomalies and associated features present in these cases--solitary median maxillary central incisor, choanal atresia, and holoprosencephaly--is described, and the literature related to the features, including genetic studies in these conditions, is reviewed. We relate our findings in these cases to current knowledge of developmental embryology. It is hoped that the findings, together with our interpretation of them, will help to clarify understanding of solitary median maxillary central incisor syndrome. This syndrome was previously considered a simple midline defect of the dental lamina, but it is now recognized as a possible predictor of holoprosencephalies of varying degrees in the proband, in members of the proband's family, and in the family's descendants.

Care of adolescents with cleft lip and palate: the role of the general dental practitioner.

Management of the adolescent with cleft lip and/or palate is ideally undertaken by a cleft palate team which has overseen care since birth, and which provides, in a paediatric hospital setting, the specialist medical, dental and ancillary care services necessary for optimal management. However, in some countries such a team is not available and individual dental practitioners and dental specialists have to undertake the necessary treatment. This is facilitated in Australia by the Federal Government's 'Cleft Lip and Palate Scheme', which subsidizes all medical and dental treatment related to the congenital defect up to 22 years of age. In such circumstances the general dental practitioner or paedodontist may need to assume an important coordinating role. The timing and integration of phases of general dental, minor oral surgical, orthodontic, periodontic and prosthetic treatment with plastic, ENT and maxillofacial surgery, speech therapy and audiology may become his responsibility. In addition, the provision of a high standard of preventive and general dental care for the cleft patient must be maintained. To carry out this coordinating role effectively, the general dentist must know his patient and family well; must understand the current concepts, objectives, treatment and investigatory techniques used in all aspects of cleft palate management; he should be aware of the genetics of the clefting conditions, medical problems which may commonly be associated with clefts and the cleft as one feature of a syndrome. Most importantly, he should be aware of the special social adjustment problems faced by many cleft adolescents in relation to their perceived 'different' facial appearance and speech.

Insulin regulates expression of metabolic genes through divergent signaling pathways.

The regulation of metabolic gene expression is a major mechanism by which insulin modulates glucose homeostasis. Defective transcription factors or signal transduction molecules that are required for insulin regulated gene expression could contribute to insulin resistance. The phosphoenolpyruvate carboxykinase (PEPCK) and hexokinase II (HKII) genes are involved in metabolic processes that represent opposing facets of glucose homeostasis, namely gluconeogenesis and glucose utilization. The regulation of the PEPCK and HKII genes by insulin has been studied in great detail at the level of both transcription and signal transduction. Recent work on the insulin signaling pathways that lead to down-regulation of PEPCK gene expression and upregulation of HKII gene expression has shown that they both require activation of phosphatidylinositol 3-kinase (PI3K) for the transmission of the insulin signal. However, the pathways diverge after PI3K and lead to activation of different downstream effectors. In this paper we review the results of studies on the transcriptional regulation of these genes by insulin and the signal transduction pathways that mediate these responses.

Dental management of the chronically ill child.

Recent advances in the medical management of chronically ill children are of interest to the general dental practitioner in those areas which relate to groups of child patients frequently treated in practice. There is now a greater understanding of the effects on the child with a chronic illness or handicap of multiple visits to hospital or medical consultants, and of hospitalization for extended periods with separation from parents and family. The bearing this has on our dental management of such children is considered, as also are the recent advances in the care of children with congenital cardiac defects, haematological disorders, and neurological disturbances.

Congenital adrenal hyperplasia and enamel hypoplasia: case report.

A female with congenital adrenal hyperplasia and enamel defects involving the permanent maxillary incisors and all canines and premolars received composite veneer splint overlays under general anesthesia. Possible etiological factors involved in the formation of the enamel defects and overall case management is discussed.

Dental health of children with cerebral palsy following sialodochoplasty.

Drooling occurs commonly in children with cerebral palsy (CP). Surgical procedures, known as slalodochoplasties, are often performed for the control of drooling. These include major salivary gland excision, parasympathetic nerve section, duct ligation, and duct re-routing. Alterations in saliva amount, flow, and consistency occur following sialodochoplasty, and the resultant effect on dental homeostasis requires further investigation. This controlled study investigated 19 children with CP following sialodochoplasty (surgery group) and 75 children with CP treated nonsurgically (control group) who attended our hospital. Dental caries experience-including dmft, DMFT, and partial DMFS scores of mandibular incisors and canines only-plaque index, and enamel developmental defects index were recorded. Saliva buffering capacity and bacterial counts were assessed. The surgical group (median DMFT = 5.00) had significantly more dental caries when compared with the control group (median DMFT = 0.00), Wilcoxon Signed-rank Test, P < 0.0001. This study has shown that children with CP following sialodochoplasty have increased risk of dental caries when compared with those treated nonsurgically for drooling. Although no caries predictors were identified, alterations to the caries-protective role of saliva are considered the likely cause. Children who undergo this procedure should receive intensive pre- and postsurgical preventive dental therapy.

The role of CT, MRI and 3D imaging in the diagnosis of temporomandibular joint and other orofacial disorders in children.

Advances in medical imaging techniques add a new third dimension (3D computer reconstruction of CT, MR and Ultrasound images) to the diagnostic armamentarium of practitioners in orofacial medicine, surgery and Orthodontics. In particular, Computerized Tomography and Magnetic Resonance Imaging with, to a lesser extent, Nuclear Medicine Imaging and Sonography provide more accurate and detailed information on abnormalities and disorders of craniofacial osseous and soft tissues, especially the temporomandibular joint, than was previously available from plain films or tomography. Greater familiarity with these new imaging modalities by dental specialists will result in their more effective use in paediatric patients.