FRACTURE OF ABUTMENT SCREW SUPPORTING A CEMENTED IMPLANT-RETAINED PROSTHESIS WITH EXTERNAL HEXAGON CONNECTION: A CASE REPORT WITH SEM EVALUATION

One of the causes of implant failures in cemented implant-retained prostheses is the fracture of abutment screw or UCLA abutment. This article reports a case of simultaneous fracture of two UCLA abutments screws occurring in an implant-supported prosthesis placed in the mandibular molar region. The fractured structures were examined under scanning electron microscopy to investigate the probable causes of the failure, which were not related to failures on materials or fabrication of the screws, but rather were due to shear forces. The misfit in cemented prostheses may be the most likely cause of shear force generation.     

A new diagnostic method of spondylodiscitis. Magnetic resonance imaging

Twenty four patients who were hospitalized for a suspicion of spondylodiscitis were prospectively evaluated with magnetic resonance imaging (MRI), radiology and radionuclide studies. Fifteen patients had an infectious spondylodiscitis, four had a vertebral degenerative disease, four had a rheumaticus spondylodiscitis, one had a chemical spondylodiscitis. The microbiological examinations and the clinical development bore the diagnosis out. Seven patients underwent Indium 111 scanning. The results of this scanning were correlated with MRI results. The MRI was performed with a 0.35 T whole body superconducting unit using spin echo technique. All patients were studied in the sagittal plane with two pulse sequences and more often with a surface-coil: TR 500 msec./TE 28 msec. and TR 2,000 msec./TE 60 msec. In all cases of true infectious spondylodiscitis the MRI results finding were characteristics. On the image obtained with the TR 500 msec./TE 28 msec., there was a confluent decreased signal intensity from the vertebral bodies and the intervertebral disk space. On the image obtained with TR 2,000 msec./TE 60 msec. there was an increased signal intensity from the vertebral bodies and the intervertebral disk space. The other spondylodiscitis have given a different MRI imaging, it was a confluent decreased signal intensity from the vertebral bodies and the intervertebral disk space on the twice pulse sequences. different images were obtained during the evolution of the infectious: first we observed a modification of the vertebral signal then the typical image that we described then a normal signal of the vertebral bodies with a pathological signal from the intervertebral disk space at last a degenerative intervertebral disk.(ABSTRACT TRUNCATED AT 250 WORDS)     

Obtention of a photo-induced adduct between a vitamin and an essential aminoacid. Binding of riboflavin to tryptophan

Studies in animals have suggested that the products of the irradiation of tryptophan in the presence of riboflavin may play a role in the development of hepatic dysfunction during parenteral nutrition. In this paper we describe the formation of an adduct between tryptophan and riboflavin obtained as a consequence of an anaerobic irradiation of these compounds. Through the use of molecular sieves and of an ion-exchange resin it was possible to separate the photo-adduct from the dimer riboflavin and other reaction products. The various fractions were characterized on the basis of their absorption and emission spectra. Also used were measures of anisotropy of fluorescence emission in order to characterize the derived adduct.     

Enhanced dispersion of atrial refractoriness as an electrophysiological substrate for vulnerability to atrial fibrillation in patients with paroxysmal atrial fibrillation.

Atrial electrical remodeling plays a part in recurrence of atrial fibrillation (AF). It has been related to an increase in heterogeneity of atrial refractoriness that facilitates the occurrence of multiple reentry wavelets and vulnerability to AF. AIM: To examine the relationship between dispersion of atrial refractoriness (Disp_A) and vulnerability to AF induction (A_Vuln) in patients with clinical paroxysmal AF (PAF). METHODS: Thirty-six patients (22 male; age 55+/-13 years) with > or =1 year of history of PAF (no underlying structural heart disease--n=20, systemic hypertension--n=14, mitral valve prolapse--n=1, surgically corrected pulmonary stenosis--n=1), underwent electrophysiological study (EPS) while off medication. The atrial effective refractory period (AERP) was assessed at five different sites--high (HRA) and low (LRA) lateral right atrium, high interatrial septum (IAS), proximal (pCS) and distal (dCS) coronary sinus--during a cycle length of 600 ms. AERP was taken as the longest S1-S2 interval that failed to initiate a propagation response. Disp_A was calculated as the difference between the longest and shortest AERP. A_Vuln was defined as the ability to induce AF with 1-2 extrastimuli or with incremental atrial pacing (600-300 ms) from the HRA or dCS. The EPS included analysis of focal electrical activity based on the presence of supraventricular ectopic beats (spontaneous or with provocative maneuvers). The patients were divided into group A--AF inducible (n=25) and group B--AF not inducible (n=11). Disp_A was analyzed to determine any association with A_Vuln. Disp_A and A_Vuln were also examined in those patients with documented repetitive focal activity. Logistic regression was used to determine any association of the following variables with A_Vuln: age, systemic hypertension, left ventricular hypertrophy, left atrial size, left ventricular function, duration of PAF, documented atrial flutter/tachycardia and Disp_A. RESULTS: There were no significant differences between the groups with regard to clinical characteristics and echocardiographic data. AF was inducible in 71% of the patients and noninducible in 29%. Group A had greater Disp_A compared to group B (105+/-78 ms vs. 49+/-20 ms; p=0.01). Disp_A was >40 ms in 50% of the patients without A_Vuln and in 91% of those with A_Vuln (p=0.05). Focal activity was demonstrated in 14 cases (39%), 57% of them with A_Vuln. Disp_A was 56+/-23 ms in this group and 92+/-78 ms in the others (p=0.07). Using logistic regression, the only predictor of A_Vuln was Disp_A (p=0.05). CONCLUSION: In patients with paroxysmal AF, Disp_A is a major determinant of A_Vuln. Nevertheless, the degree of nonuniformity of AERP appears to be less important as an electrophysiological substrate for AF due to focal activation.     

Impact of a specialized outpatient heart failure follow-up program on hospitalization frequency and functional status of patients with advanced heart failure.

BACKGROUND: High rates of morbidity and mortality are observed in patients with advanced heart failure (AHF). AHF is now considered the most costly syndrome in cardiology owing to the substantial economic burden associated with hospitalizations for acute decompensation. A management program that involves specialized follow-up by a multidisciplinary team has been suggested as a desirable strategy for improving outcomes for these patients. ObjectivE: To evaluate the impact of a specialized outpatient heart failure (HF) follow-up program for patients with AHF on frequency and duration of hospitalization for HF and functional status. METHODS: We retrospectively studied 167 consecutive patients with AHF who were referred to the outpatient HF follow-up program in our institution between January and November 2002, of whom 147 followed for > or =30 days were included in the analysis. In addition to demographic and baseline clinical characteristics, HF medication and NYHA functional class, the number and duration of hospitalizations for HF during the previous 12 months were recorded and compared at the time of referral and after a follow-up period of 6.5+/-3 months. RESULTS: Of the 147 patients analyzed (aged 60.8+/-13 years; 79% male; left ventricular ejection fraction 27+/-11%), 67% were in NYHA functional class III, 20% in class II and 13% in class IV at the time of referral. There was a significant improvement in functional class during the mean follow-up period: 55% of the patients were in class III, 37% in class II, 5% in class I and 3% in class IV (p<0.0001). The proportion of patients on beta-blockers or spironolactone increased from 33% and 51% at the time of referral to 69% and 71% respectively after referral (p<0.0001). In the 12 months before referral, 39% of the patients had been hospitalized for acute decompensation of HF (87 hospitalizations - mean 7.2/month) versus 13% of the patients during the mean follow-up period (25 hospitalizations - 3.8/month, p<0.0001). No significant differences were found in the proportion of patients on angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers, digoxin or diuretics, or in the mean duration of hospitalization before and after referral. ConclusioN: The specialized follow-up of patients with AHF by a team with expertise in HF resulted in significant therapeutic optimization. Increased use of beta-blockers and spironolactone was associated with significant improvement in functional capacity and significant reduction in hospitalizations.     

The nocturnal jejunal migrating motor complex: defining normal ranges by study of 51 healthy adult volunteers and meta-analysis

Interdigestive human small bowel motility is characterized by the migrating motor complex (MMC). The aims of this study were to: (i) establish the normal range of variables of the nocturnal jejunal MMC and (ii) incorporate these data in a subsequent meta-analysis. Eighty-one recordings were performed by prolonged (24 h) ambulatory manometry in 51 subjects in two centres. Quantitative analysis was undertaken of 419 Phase III and 332 Phase II episodes. Adjusted mean values of seven variables were calculated using a mixed-effects model. Meta-analysis of pooled published data to generate a reliable 95% reference range was also performed. Adjusted mean values and confidence intervals are presented for all seven variables. Intrasubject variances were large in comparison with intersubject. Meta-analysis of 19 studies (356 pooled patients) meeting inclusion criteria produced wide reference ranges. At least five such ranges are useful for the detection of abnormality in the individual. This is the largest study of normal volunteers presented to date, with ranges for many variables produced using appropriate statistical methodology. A model for definition of abnormality has been proposed. We recommend that these data may be used by investigators in this field as a complement to other existing indicators of small bowel dysmotility.     

Estimation of salt intake by urinary sodium excretion in a Portuguese adult population and its relationship to arterial stiffness.

BACKGROUND: Portugal has one of the highest mortality rates from stroke, a high prevalence of hypertension and probably a high salt intake level. AIM: To evaluate Portuguese salt intake levels and their relationship to blood pressure and arterial stiffness in a sample of four different adult populations living in northern Portugal. METHODS: A cross-sectional study evaluating 24-hour urinary excretion of sodium (24 h UNa+), potassium and creatinine, blood pressure (BP), and pulse wave velocity (PWV) as an index of aortic stiffness in adult populations of sustained hypertensives (HT), relatives of patients with previous stroke (Fam), university students (US) and factory workers (FW), in the context of their usual dietary habits. RESULTS: We evaluated a total of 426 subjects, mean age 50 +/- 22 years, 56% female, BMI 27.9+/-5.1, BP 159/92 mmHg, PWV 10.4+/-2.2 m/s, who showed mean 24h UNa+ of 202 +/- 64 mmol/d, corresponding to a daily salt intake of 12.3 g (ranging from 5.2 to 24.8). The four groups were: HT: n = 245, 49 +/- 18 years, 92% of those selected, 69% treated, BP 163/94 mmHg, PWV 11.9 m/s, 24 h UNa+ 212 mmol/d, i.e. 12.4 g/d of salt); Fam: n = 38, 64 +/- 20 years, 57 % of those selected, BP 144/88 mmHg, PWV 10.5 m/s, 24 h UNa+ 194 mmol/d, i.e. 11.1 g/d of salt; US: n = 82, 22 +/- 3 years, 57% of those selected, BP 124/77 mmHg, PWV 8.7 m/s, 24h UNa+ 199 mmol/d, i.e. 11.3 g/d of salt; FW: n = 61, 39 9 years, 47% of those selected, BP 129/79 mmHg, PWV 9.5 m/s, 24 h UNa+ 221 mmol/d, i.e. 12.9 g/d of salt. The ratio of urinary sodium/potassium excretion (1.9 (0.4) was significantly higher in HT than the other three groups. In the 426 subjects, 24h UNa+ correlated significantly (p < 0.01) with systolic BP (r = 0.209) and with PWV (r=0.256) after adjustment for age and BP. Multivariate analysis showed that BP, age and 24h UNa+ correlated independently with PWV taken as a dependent variable. CONCLUSIONS: Four different Portuguese populations showed similarly high mean daily salt intake levels, almost double those recommended by the WHO. Overall, high urinary sodium excretion correlated consistently with high BP levels and appeared to be an independent determining factor of arterial stiffness. These findings suggest that Portugal in general has a high salt intake diet, and urgent measures are required to restrict salt consumption in order to prevent and treat hypertensive disease and to reduce overall cardiovascular risk and events.