Digital evaluation of the dimensional accuracy of four different implant impression techniques.

AIMS: The aim of this study was to compare the dimensional accuracy of four different implant impression techniques of a mandibular edentulous model with five parallel implants. MATERIALS AND METHODS: Five dental implants were placed in an edentulous mandibular model in parallel. A total of forty impressions were obtained using four different impression techniques. In Group 1 (G1) and Group 2 (G2), closed tray impressions with and without plastic caps, respectively, were used. In Group 3 (G3) and Group 4 (G4), open tray impressions with a direct splinted technique and an improved direct splinted technique, respectively, were used. All the impressions were poured with Type IV dental stone. Master model and study casts were scanned with a laser optical scanner and aligned by observing the superpositions of the anatomical landmarks using a software program. STATISTICAL ANALYSIS USED: Fifty measurements of the apical, coronal, and angular discrepancies of the master and study casts were obtained (n = 50) and statistically analyzed using a one-way analysis of variance and post hoc (least significant difference ) and Friedman's tests. RESULTS: The lowest accuracy was obtained from G2 when the angular (1.48°), coronal (0.32 µm), and apical (0.14 µm) deviations were tested (P < 0.05), whereas no statistically significant differences were found among the other groups (P < 0.05). CONCLUSIONS: In cases with five parallel mandibular implants, improved accuracy was achieved using the direct splinted technique, the improved direct splinted technique, or the closed tray impression technique with snap on plastic caps.

Molecular evolution of the human interleukin-8 receptor gene cluster.

Interleukin-8 (IL-8) is the prototype for a family of at least eight neutrophil chemoattractants whose genes map to human chromosome 4q13-q21. Two human IL-8 receptors, IL8RA and IL8RB, are known from cDNA cloning; IL8RA is a promiscuous receptor for at least two other related ligands, GRO alpha and NAP-2. We now report cloning of the genes for IL8RA, IL8RB and a recently inactivated pseudogene of receptor A (IL8RAP). These form a cluster of only three genes in the superfamily of G protein-coupled receptors (GPCRs) and map to 2q34-q35. The coevolutionary diversity displayed by the IL-8 ligand-receptor complex--ligand promiscuity for IL-8, receptor promiscuity for IL8RA, gene duplication for both ligands and receptors and gene extinction in the case of IL8RAP--is unprecedented for the GPCR superfamily.

Small nuclear ribonucleoprotein polypeptide N (SNRPN), an expressed gene in the Prader-Willi syndrome critical region.

Prader-Willi syndrome (PWS) is associated with paternally derived chromosomal deletions in region 15q11-13 or with maternal disomy for chromosome 15. Therefore, loss of the expressed paternal alleles of maternally imprinted genes must be responsible for the PWS phenotype. We have mapped the gene encoding the small nuclear RNA associated polypeptide SmN (SNRPN) to human chromosome 15q12 and a processed pseudogene SNRPNP1 to chromosome region 6pter-p21. Furthermore, SNRPN was mapped to the minimal deletion interval that is critical for PWS. The fact that the mouse Snrpn gene is maternally imprinted in brain suggests that loss of the paternally derived SNRPN allele may be involved in the PWS phenotype.

Maternal imprinting of the mouse Snrpn gene and conserved linkage homology with the human Prader-Willi syndrome region.

Prader-Willi syndrome (PWS) is associated with paternal gene deficiencies in human chromosome 15q11-13, suggesting that PWS is caused by a deficiency in one or more maternally imprinted genes. We have now mapped a gene, Snrpn, encoding a brain-enriched small nuclear ribonucleoprotein (snRNP)-associated polypeptide SmN, to mouse chromosome 7 in a region of homology with human chromosome 15q11-13 and demonstrated that Snrpn is a maternally imprinted gene in mouse. These studies, in combination with the accompanying human mapping studies showing that SNRPN maps in the Prader-Willi critical region, identify SNRPN as a candidate gene involved in PWS and suggest that PWS may be caused, in part, by defects in mRNA processing.

Survival of root canal-treated teeth adjacent to an implant: A retrospective case-control study.

OBJECTIVES: To evaluate the survival of root canal treated (RCT) teeth adjacent to an implant compared with that of RCT teeth of the same patient non-adjacent to an implant. MATERIALS AND METHODS: RCT tooth of each patient adjacent to an implant were included in the test group. The control group consisted of another RCT tooth of the same patient; the control RCT tooth was not adjacent to an implant and selected to be of the same type of the RCT tooth in the test group. 72 teeth of 36 patients with at least 4-year follow-up were included. In addition to survival, other clinical and demographic parameters investigated were age, sex, tooth type and position, presence of a crown, presence of retreatment, presence of a post-core, presence of adjacent edentulous area, presence of implant-supported fixed prosthetic restoration on the antagonist tooth and periapical health status. Pearson Chi-Square and Fisher Exact tests were used to compare the test and the control groups with categorical variables (α=0.05). Survival curves were obtained by the Kaplan-Meier method, and the Log-rank test was performed to compare the survival probabilities (α=0.05). RESULTS: No significant difference in survival rates was observed between the test and the control groups (p = 0.72). Similarly, no significant relationship was found between the investigated clinical variables and the survival rates of RCT teeth (p>0.05). Survival times differed depending on the presence of an adjacent edentulous area (p<0.001) and the periapical health status (p = 0.026). CONCLUSIONS: RCT teeth with unhealed periapical tissues had a shorter cumulative survival time. Similarly, those adjacent to an edentulous area had shorter cumulative and complication-free survival times. CLINICAL SIGNIFICANCE: This is the first study to determine the survival outcome of a RCT tooth adjacent to an implant compared to a non-adjacent one in the same patient. Being adjacent to an implant did not have a detrimental effect on the survival time and rate of RCT teeth.

Bacillus spp. among hospitalized patients with haematological malignancies: clinical features, epidemics and outcomes.

Between April 2000 and May 2005, 350 bacteraemic episodes occurred among patients treated in our haematology unit. Two hundred and twenty-eight of these episodes were caused by Gram-positive pathogens, most commonly coagulase-negative staphylococci and Staphylococcus aureus. One hundred and twenty-two episodes were due to Gram-negative pathogens, with a predominance of Escherichia coli, Acinetobacter baumannii and Pseudomonas aeruginosa. Bacillus bacteraemias constituted 12 of these episodes occurring in 12 patients, and accounted for 3.4% of all bacteraemic episodes. Of the 12 strains evaluated, seven were Bacillus licheniformis, three were Bacillus cereus and two were Bacillus pumilus. Seven episodes presented with bloodstream infection, three with pneumonia, one with severe abdominal pain and deterioration of liver function, and one with a catheter-related bloodstream infection. B. licheniformis was isolated from five patients who had been hospitalized at the same time. This outbreak was related to non-sterile cotton wool used during skin disinfection. B. cereus and B. licheniformis isolates were susceptible to cefepime, carbapenems, aminoglycosides and vancomycin, but B. pumilus isolates were resistant to all antibiotics except for quinolones and vancomycin. Two deaths were observed. In conclusion, Bacillus spp. may cause serious infections, diagnostic and therapeutic dilemmas, and high morbidity and mortality in patients with haematological malignancies. Both B. cereus and B. licheniformis may be among the 'new' Gram-positive pathogens to cause serious infection in patients with neutropenia.

Human MLH1 deficiency predisposes to hematological malignancy and neurofibromatosis type 1.

Heterozygous germ-line mutations in the DNA mismatch repair genes lead to hereditary nonpolyposis colorectal cancer. The disease susceptibility of individuals who constitutionally lack both wild-type alleles is unknown. We have identified three offspring in a hereditary nonpolyposis colorectal cancer family who developed hematological malignancy at a very early age, and at least two of them displayed signs of neurofibromatosis type 1 (NF1). DNA sequence analysis and allele-specific amplification in two siblings revealed a homozygous MLH1 mutation (C676T-->Arg226Stop). Thus, a homozygous germ-line MLH1 mutation and consequent mismatch repair deficiency results in a mutator phenotype characterized by leukemia and/or lymphoma associated with neurofibromatosis type 1.

Frequent demonstration of human herpesvirus 8 (HHV-8) in bone marrow biopsy samples from Turkish patients with multiple myeloma (MM).

In order to investigate the frequency of HHV-8 in MM patients from another geographic location, we obtained fresh bone marrow (BM) biopsies from Turkish patients with MM (n = 21), monoclonal gammopathy of undetermined significance (MGUS) (n = 2), plasmacytoma (n = 1) with BM plasma cell infiltration, various hematological disorders (n = 6), and five healthy Turkish controls. The frequency of HHV-8 was analyzed by polymerase chain reaction (PCR) in two independent laboratories in the USA and in Turkey. Using fresh BM biopsies, 17/21 MM patients were positive for HHV-8 whereas all five healthy controls, and six patients with other hematological disorders were negative. Two patients with MGUS, and one patient with a solitary plasmacytoma were also negative. The data from the two laboratories were completely concordant. Also using primer pairs for v IRF and v IL-8R confirmed the results observed with the KS330233 primers. Furthermore, sequence analysis demonstrated a C3 strain pattern in the ORF26 region which was also found in MM patients from the US. Thus, HHV-8 is present in the majority of Turkish MM patients, and the absence of the virus in healthy controls further supports its role in the pathogenesis of MM.

Germ line BRCA1 and BRCA2 gene mutations in Turkish breast cancer patients.

Germ line BRCA1 and/or BRCA2 mutations were screened in 50 Turkish breast and/or ovarian cancer patients composed of hereditary, familial, early onset and male cancer groups. Genomic DNA samples were tested by heteroduplex analysis and DNA sequencing. Two truncating BRCA2 mutations, one novel (6880 insG) and one previously reported (3034 delAAAC), were found in two out of six (33%) hereditary breast and/or ovarian cancer patients. A novel truncating (1200 insA) and a missense (2080A-->G) BRCA1 mutation was found in two of 27 (7%) individuals in the early onset group. A total of four (8%) disease-causing mutations in 50 breast cancer patients were identified in BRCA1 and BRCA2 genes. In addition, five BRCA1 sequence variants have been identified in 23 patients. These results indicate that BRCA1 and BRCA2 genes are involved in some, but not all, forms of hereditary predisposition to breast cancer in the Turkish population.

Segmental distribution of muscle weakness in SMA III: implications for deterioration in muscle strength with time.

We examined 26 spinal muscular atrophy type III (SMA III) patients with SMNt deletions, searching for possible segmental distribution of muscle weakness. In those with disease duration of < or = 11 years, the weakest muscles were upper lumbar innervated ones in the lower extremities. In the upper extremities, early involvement of triceps muscle suggested the possibility of lower cervical (C7) onset. Electrophysiologically, weaker muscles had a more severe reduction in the recruitment pattern, particularly in the lower extremities. However, severe reduction in recruitment was sometimes also observed in clinically strong muscles. In patients with disease duration of > or = 16 years and regardless of disease duration, in those with disease onset at < or = 3 years of age, weakness and severe electrophysiological changes were more widespread. These findings may suggest a progression in muscle weakness with time. When compared to 12 patients with Becker muscular dystrophy (BMD), early stage SMA III with weak iliopsoas-strong gluteus maximus stood in contrast to BMD with weak gluteus maximus-strong iliopsoas.

A renal transplant recipient with pulmonary tuberculosis and visceral leishmaniasis: review of superimposed infections and therapy approaches.

Visceral leishmaniasis (VL) is an acute or subacute disease that is almost invariably fatal if untreated. It is a rare disease in renal transplant recipients and frequently reported together with other infectious agents. A 39-year-old renal transplant patient was admitted to hospital for elective coronary surgery. In the post-operative period, he developed spiking fever and non-productive cough and his general condition deteriorated. While he was taking medication for non-specific pneumonia, a cavitary lesion occurred in his lung, and he had the diagnosis of pulmonary tuberculosis and antituberculous treatment was started. Despite treatment, his fever continued. As the patient developed pancytopenia and splenomegaly, a bone marrow aspiration was done. Evaluation of bone marrow aspirate indicated Leishmania parasites. He was successfully treated with a more intensive liposomal amphotericin (L-AmB). Complete cure was achieved during follow-up period of 10 months without clinical relapse. In the existence of fever and long-standing pancytopenia, VL should be suspected although the patient had another proved infection and did not live or visit an endemic area. L-AmB usage can be safely preferred for treatment of selected renal transplant recipients with VL as first-line therapy.

Malignant peritoneal mesothelioma following asbestos exposure.

Clinical, epidemiological, and pathological studies have demonstrated that asbestosis plays a major role in the etiology of mesothelioma. The direct exposure of workers in industrialized countries to asbestos fibers and nonoccupational household contact elevate the risk of malignant mesothelioma. An increased risk has been found in certain geographic areas of Turkey due to the presence of asbestos deposits and the use of the material known as "white soil" as an insulation. We present a malignant mesothelioma case from rural eastern Turkey with a history of asbestos exposure from using "white soil". We review the epidemiological aspects of asbestos as they relate to mesothelioma.

Multiple myeloma in the region of Bursa, Turkey: a retrospective analysis.

We evaluated the clinical and laboratory features of multiple myeloma in our patients and reviewed the factors that affected their survival. The study included 36 patients (12 women and 24 men) with multiple myeloma whom we followed up until death between October 1978 and June 1995. The age range was 34 to 75 years (mean age, 53.9). The chief complaints on admission were lumbar pain and pain in the extremities (77.8%) and generalized weakness (61.1%). The most common laboratory findings were severe anemia (hemoglobin < 8.0 g/dl) (50%), elevated erythrocyte sedimentation rate (75%), monoclonal spike in the serum protein electrophoresis (44.4%), and lytic skull lesions (72.2%). Twenty-three (64%) patients had a monoclonal IgG, 9 (25%) had IgA, 1 had IgD, 2 had light chain disease, and 1 was nonsecretory. Localized plasmacytoma was detected in 4 patients and 4 patients had amyloidosis in rectal and gingival biopsies. According to the Durie-Salmon staging system, 2 patients were in stage 1, 8 were in stage 2, and 26 were in stage 3. The mean survival was 31.4 +/- 4.3 months (range: 1 to 96). The 5-year survival rate was 11%. Sex, age at diagnosis, stage of the disease, hemoglobin level, platelet count, level of serum calcium, creatinine, serum paraprotein, and type of paraproteinemia were tested as prognostic parameters. We could not establish a statistically meaningful effect of these parameters on survival time. The first and second most common causes of death were renal failure and infection, respectively.

Survey of factor V leiden and prothrombin gene mutations in systemic lupus erythematosus.

The two most common hereditary risk factors for thrombosis are factor V Leiden mutation and a prothrombin gene mutation. There is indeed a thrombotic tendency in patients with systemic lupus erythematosis (SLE) and it is not always associated with antiphospholipid antibodies. We aimed to determine the relationship between both factor V Leiden and prothrombin gene mutations and SLE. Using polymerase chain reaction (PCR) the factor V Leiden and prothrombin gene mutations were evaluated in 55 patients (20 children and 35 adults) with SLE. Although seven patients were found to have factor V Leiden mutation in the heterozygous state, two had the heterozygous G-->A (20210) prothrombin gene mutation. Although one had these two mutations concurrently, these two patients did not have thrombosis. The factor V Leiden mutation frequency (12.7%) was higher than that of our general population (7.1%). On the other hand, seven of the patients with SLE had a thrombotic event. Although of these seven, four (57%) had factor V Leiden mutation, three (43%) had no mutation. Of 48 patients with no thrombotic history, only three had the factor V mutation (6.25%). The prevalence of the factor V Leiden mutation in SLE patients with and without thrombosis was significantly different by Fisher's exact test (p<0.05). The risk of venous thrombosis in patients with factor V Leiden increased threefold compared to that in those without factor V Leiden mutation (odds ratio 20.1; CI 2.99-133.6). Although factor V Leiden mutation seems to play a role in the development of venous thrombosis in SLE, the development of thrombosis in SLE is multifactorial.

Platysma myocutaneous flap: use for intraoral reconstruction.

Twenty patients were treated for intraoral epidermoid carcinoma with a single-stage reconstructive technique using a myocutaneous flap based on the platysma muscle. This flap carries on its distal tip a portion of isolated cervical skin to be used for intraoral replacement of the resected tissue. The superior vascular pedicle, the submental branch of the facial artery, was used. The platysma skin flap will survive if the blood supply from at least one region is preserved. In addition, it may be beneficial to include the external jugular and/or the communicating veins in the flap. Only three minor complications were seen and healed spontaneously. The flap has proved to be highly reliable and has significant benefits over many other techniques commonly used for head and neck reconstruction.

Auditory nerve-brainstem responses in cystic fibrosis patients.

We conducted a study in 30 children with cystic fibrosis (CF) to determine if their hearing had been affected. Their ages ranged between 2 to 17 years and they were studied by means of complete audiologic evaluation and brainstem evoked response audiometry (BERA). Twenty of them had received some ototoxic drugs for variable periods. The results showed that there was no significant correlation between CF and BERA findings. The findings indicated that, except a few middle ear problems such as serous otitis media, CF did not affect hearing status of the CF children per se.

Audiologic and impedancemetric findings within thalassaemic patients.

The objective of this study is to investigate hearing losses in thalassaemic patients. This study was conducted on 34 thalassemic patients of which 27 of them had thalassaemia major and the remaining 7 had thalassaemia intermedia. Six (11.11%) of the 54 ears with thalassaemia major were found to have normal hearing. Thirty-two ears (59.26%) had conductive hearing loss, 8 ears (14.81%) had mixed type of hearing loss. Moreover, in this group, there was no ear which had pure sensorineural hearing loss. Of the majority of patients having thalassaemia major and thalassaemia intermedia, an air bone gap was found even though there was no negative pressure in the middle ear. In these patients a high degree of static compliance and normal shaped, stiff amplitude, normal pressure tympanograms were observed. Moreover, in most of these patients acoustic reflexes were not obtained. These findings are rather interesting since they show the pathological changes which may cause stiffness in the middle ear sound transmission system.

Tuberculosis of the parotid salivary gland.

An interesting and rare case of tuberculosis involving a parotid gland is discussed. Although pulmonary tuberculosis is not uncommon in Turkey, primary parotid gland involvement is rare. The patient was treated by parotidectomy and antituberculous chemotherapy.

Ear, nose and throat findings in cystic fibrosis patients.

An ear-nose-throat survey was carried out on 30 children with cystic fibrosis (CF) between two and 17 years of age. There were three (10%) confirmed cases of secretory otitis media. One child had previous surgery for polyps. Ten children had chronic pansinusitis mildly responsive to medical therapy. Hypertrophy of the nasal conchae was detected in eight cases. The data showed that the risk of ear-nose-and-throat disease was increased in CF patients, but audiologic problems are not very common in CF patients. CF should be kept in mind in children who have nasal polyps, hypertrophied turbinates or sinusitis unresponsive to medical therapy.

Evaluation of chimerism with DNA polymorphisms in bone marrow transplantation.

Evaluation of chimeric status following allogenic BMT is an important tool for monitoring the replacement of host cells with donor cells and for determining the risk of relapse. Polymorphic DNA sequences can be used as powerful markers in identification of donor/recipient genotype differences, even between close relatives. Polymerase chain reaction (PCR) amplification of three variable number of tandem repeat (VNTR) loci and five single-locus polymorphisms (SLP) was used to identify chimerism in 40 recipient-donor pairs. Mixed chimerism was present in 11 patients, and complete chimerism in 29. This PCR method is a rapid and sensitive assay to detect engraftment and evaluate relapse potential, and thus is very useful in the clinical management of BMT patients.