Haptics Vs Typodonts for Crown Preparation in Undergraduate Dental Student Education.

OBJECTIVES: This study aims to compare students' subjective perceptions and objective results by comparing two methods of crown preparation: typodonts and haptics. MATERIALS AND METHODS: Fifty-four second-year students were given instructions on crown preparation for the upper right second premolar. First on typodonts and then with haptics. They were given five minutes to familiarize with the artificial environment and then thirty minutes for the actual preparation. Finally, they completed a questionnaire about their experience. Their preparations were objectively compared by measuring the angle of total occlusal convergence-TOC on the typodonts and with haptics. RESULTS: Students reported that haptics can enhance the learning process and that they would use them for skill training in the future. Overall, their experience was rated as positive. The TOC of teeth prepared with haptics was significantly higher than those prepared with typodonts, but all values were within the acceptable range. CONCLUSION: Although students did not prefer haptics to typodonts, haptics appear to be a powerful tool in the educational process because it can be a complementary option to traditional methods at the preclinical level.

Rituximab monotherapy is highly effective in splenic marginal zone lymphoma.

Splenectomy has traditionally been considered as a standard first line treatment for splenic marginal zone lymphoma (SMZL) conferring a survival advantage over chemotherapy. However it carries significant complications, especially in elderly patients. The purpose of this retrospective study was to report our experience on the efficacy of Rituximab as first line treatment in 16 consecutive SMZL patients, diagnosed in our department. The diagnosis was established using standard criteria. Patients' median age was 57 years (range, 48-78). Prior to treatment initiation all patients had splenomegaly, nine had anemia, five lymphocytosis, five neutropenia and six thrombocytopenia. Rituximab was administered at a dose of 375 mg/m2/week for 6 consecutive weeks. The overall response rate was 100%. After treatment, all patients had a complete resolution of splenomegaly along with restoration of their blood counts. Eleven patients (69%) achieved a CR, three (19%) unconfirmed CR and two (12%) a PR. Among the complete responders seven patients had also a molecular remission. The median time to clinical response was 3 weeks (range, 2-6). Rituximab maintenance was given to 12 patients. Eleven of them had no evidence of disease progression after a median follow-up time of 28.5 months (range, 14-36), while two out of four patients who did not receive maintenance, relapsed 7 and 24 months after the completion of induction treatment. Median follow-up time for the entire series was 29.5 months (range, 15-81). No deaths were recorded during the follow-up period. Therapy was well tolerated. The present study demonstrates that rituximab is an effective treatment for SMZL and could be considered as a substitute or alternative to splenectomy.

Angiogenesis in Hodgkin's lymphoma: a morphometric approach in 286 patients with prognostic implications.

The significance of angiogenesis in Hodgkin's lymphoma (HL) is not well defined. The aim of this study was to evaluate various morphometric characteristics of microvessels in lymph node sections of 286 patients with HL at diagnosis and investigate their relationship with clinicopathologic parameters and prognosis. Microvessel density (MVD), total vascular area (TVA) and several size- and shape-related microvascular parameters were quantitated--after anti-CD34 immunohistochemical staining--in the region of most intense vascularization, using image analysis. An increase in microvessel caliber parameters (area, perimeter, major and minor axis length) and a decrease in MVD were noted with increasing stage. An inverse relationship was recorded between MVD and the number of involved sites (NIS) and LDH. In univariate analysis, overall disease-specific survival was adversely affected by MVD and TVA, whereas inferior failure-free survival (FFS) was associated with the presence of more flattened vessel sections. Multivariate analysis disclosed that the extent of angiogenesis (MVD/TVA), age and the NIS independently affected overall survival. Accordingly, FFS was independently linked to the shape of microvessels and albumin levels or the NIS. In conclusion, our data support the view that angiogenesis in HL provides independent prognostic information, requiring the concomitant evaluation of quantitative and qualitative aspects of microvascular network.

beta(2)-microglobulin in Hodgkin's lymphoma: prognostic significance in patients treated with ABVD or equivalent regimens.

PURPOSE: Serum beta-2 microglobulin (sbeta(2)m) is an established prognostic factor for several lymphoproliferative disorders. Because its significance in Hodgkin's lymphoma (HL) is controversial, we determined sbeta(2)m levels in pretreatment serum samples of patients with HL in order to elucidate its prognostic value in this condition. PATIENTS AND METHODS: Pretreatment sbeta(2)m levels were determined in 379 HL patients who were treated with ABVD or equivalent regimens with or without radiotherapy (RT), using a radioimmunoassay (upper normal limit 2.4 mg/l). Sbeta(2)m levels were correlated with several clinical and laboratory parameters. RESULTS: Elevated sbeta(2)m levels were detected in 138/379 (36%) patients and correlated with all clinical and laboratory baseline features except gender, lung involvement and mediastinal bulk. They also correlated with serum soluble CD30 and interleukin-10 levels. The 8-year failure-free survival (FFS) was 78 -/+ 4% for patients with normal versus 65 -/+ 7% for patients with elevated sbeta(2)m levels (p=0.003). The corresponding rates among early-stage patients were 83 -/+ 53% versus 71 -/+ 9% (p=0.003), while for advanced stages they were 70 -/+ 6% versus 64 -/+ 8% (p=0.54). In multivariate analysis of the whole patient population elevation of sbeta(2)m levels was not predictive of FFS, but it was strongly predictive among early-stage patients. The 8-year overall survival (OS) rates were 91 -/+ 3% for patients with normal versus 59 -/+ 11% (p <0,0001) for patients with elevated sbeta(2)m levels, while unrelated mortality at 8 years was 1 -/+ 1% versus 27 -/+ 12% (p<0.0001). CONCLUSION: Our data suggest that sbeta(2)m levels may be a potent prognostic factor for FFS in patients with early stage HL treated with ABVD and equivalent regimens. Their effect on OS is confounded by the higher unrelated mortality in patients with elevated baseline sbeta(2)m levels, probably due to the strong association between sbeta(2)m and older age.

The effect of human platelet alloantigen polymorphisms on the in vitro responsiveness to adrenaline and collagen.

A number of clinical studies have suggested that carriage of the low frequency allele (b) of the human platelet antigen 1 (HPA-1) system is a risk factor for coronary thrombosis. We have examined the effect of a series of HPA biallelic polymorphisms (systems -1, -2, -3 and -5) on the in vitro platelet aggregation in response to adrenaline and collagen in 30 healthy volunteers. There was a significantly higher prevalence (10 out of 18) of carriers of the HPA-1b polymorphism among subjects showing a > 50% aggregation response to adrenaline ('responders') than the prevalence (1/12) in 'non-responders' (P < 0.05). Platelets heterozygous for the HPA-1b polymorphism showed a significantly higher rate (slope) and greater extent (%) of adrenaline-induced aggregation than platelets not carrying the HPA-1b allele (P < 0.05). A greater extent of collagen-induced aggregation was also demonstrated in HPA-1ab platelets (P < 0.05). Inhibition of adrenaline-induced aggregation following incubation with aspirin was greater (P < 0.01) in HPA-1ab than in HPA-1aa platelets. Collagen-induced aggregation was slower in carriers of the HPA-5b allele than in HPA-5aa subjects (P < 0.05). Polymorphisms of the HPA-2 and HPA-3 systems were not associated with different aggregation responses to either adrenaline or collagen. These results support the clinical observation that polymorphism HPA-1b may predispose to increased platelet thrombogenicity and suggest that the presence of polymorphism HPA-5b might render the platelet less reactive to collagen.

Enterococcal infections in a Greek intensive care unit: a 5-y study.

In this study we determined the incidence, resistance pattern, and mortality rate associated with infection caused by Enterococcus faecalis and Enterococcus faecium among patients in a multidisciplinary intensive care unit (ICU). A total of 111 patients with E. faecalis and 60 with E. faecium infections were identified during a 5-y period (1992-96). We observed an increase in the incidence of enterococcal infections (from 5.46 to 8.46 per 1000 patients-days, p = 0.0112), due mainly to the increased incidence of E. faecium (from 0.45 to 4.06 per 1000 patients-days, p = 0.002). Blood was the most common site of enterococcus isolation. E. faecium was more resistant to antibiotics than E. faecalis, but no vancomycin resistant enterococcus was isolated. Patients with E. faecium infection had a significantly higher mortality than patients with E. faecalis infection (66% vs. 41.5%, p = 0.0035 for infection from any site and 85.7 vs. 47.7%, p = 0.012 for bacteremic patients). r 4n- D I .- .- - .. . .

Cholestatic jaundice as a paraneoplastic manifestation of renal cell carcinoma.

Malignant diseases may cause cholestatic jaundice through either main bile duct obstruction or widespread hepatic metastasis. Renal cell carcinoma (hypernephroma, RCC) can cause a variety of paraneoplastic manifestations which can be the main presenting symptoms. Cholestasis, as a paraneoplastic syndrome, has been well described in patients with malignant lymphohyperplastic diseases. Non-metastatic nephrogenic hepatic dysfunction syndrome without jaundice has often been described in patients with hypernephroma (Stauffer's syndrome). Paraneoplastic cholestatic jaundice has not yet been described. We report, for the first time, two patients who presented with pruritus and cholestatic jaundice. During the diagnostic work-up, RCC was diagnosed. The renal tumour was an unexpected finding during computed tomographic (CT) scan. No clinical manifestations of hypernephroma, short of microscopic haematuria, were detected. Conjugated bilirubin, alkaline phosphatase and gamma-glutamyltranspeptidase were markedly increased. No hepatic metastasis or main bile duct obstruction were detected by appropriate investigations. After radical nephrectomy, liver abnormalities disappeared rapidly. We conclude that RCC should be included among neoplasms causing not only anicteric intrahepatic cholestasis but also frank jaundice as part of a paraneoplastic syndrome. The differential diagnosis from hepatic metastasis, main bile duct obstruction or other causes of jaundice is of clinical importance and of prognostic value. Patients with unexplained cholestasis should be investigated for malignant diseases including hypernephroma.