Histometric evaluation of bone regeneration around immediate implants partially in contact with bone: a pilot study in dogs

Bone regeneration was evaluated around immediate implants partially in contact with bone, with or without the concurrent application of a combination of platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF-1). Mandibular premolars were removed, and the implant osteotomies were prepared; a uniform circumferential gap was prepared 1.25 mm beyond the width of the implant bed in the coronal half. Twelve implants (8.5 x 3.75 mm) were inserted in six dogs. Before insertion, an implant received a single application of 5 micrograms/mL of PDGF and IGF-1 delivered in 0.10 mL of 4% methylcellulose gel or 0.10 mL of 4% methylcellulose gel only as a control. To label regenerated bone, a 2% calcein green solution was administered by intramuscular injection at 0, 7, 15, 30, and 45 days after implant insertion Three and 8 weeks after implant insertion undecalcified sections were obtained, and the degree of bone to implant contact, the bone area, and the intensity of bone labeling were measured into the limits of the eight most coronal threads of the implant (four threads on each side of each implant). The results showed a greater extension of bone-to-implant contact, a larger percentage of bone area, and greater intensity of bone labeling for test versus control implants (P < .01). Within the limits of the present study, it was concluded that the combination of PDGF/IGF-1 might be an alternative for enhancing bone healing around implants partially in contact with bone.     

Aetiology of chronic suppurative lung disease

Forty one (1%) of 4000 children referred for respiratory disease had chronic suppurative lung disease not due to cystic fibrosis. Further investigations showed congenital malformations in six (15%), primary ciliary dyskinesia syndrome in seven (17%), 11 had immunological abnormalities (27%), and two bronchiectasis due to aspiration (5%). Therefore the underlying cause for the disease was found in 63%. Identification of predisposing causes may facilitate prevention of further bronchial damage.     

High and low fluences of alpha-particles induce a G1 checkpoint in human diploid fibroblasts

The effects of exposure to high and very low fluence alpha-particles on the G1 checkpoint were investigated in human diploid fibroblasts irradiated and released from density-inhibited confluent cultures by the use of the cumulative labeling index method. Transient and permanent arrests in G1 occurred in fibroblast populations exposed to mean doses as low as 1 cGy, suggesting that nontraversed bystander cells may contribute to the low dose response. In cells exposed to high fluences, the G1 checkpoint is at least as extensive as in gamma-irradiated cells. In contrast to gamma-irradiated cells, neither repair of potentially lethal damage nor a reduction in the fraction of cells transiently or permanently arrested in G1 were observed in cells held in confluence for 6 h after alpha-particle irradiation. Studies with isogenic wild-type, p53-/-, and p21Waf1-/- mouse embryo fibroblasts exposed to either gamma or alpha-particle radiation revealed a total lack of G1 arrest in either p53-/- or p21waf1-/- cells, indicating that the G1 checkpoint in wild-type cells is p53-dependent and that p21Wf1 fully mediates the role of p53 in its induction. In contrast to human cells, mouse embryo fibroblasts do not undergo a permanent G1 arrest. Except under conditions favoring potentially lethal damage repair, a comparable expression pattern of p53, p21Waf1, and other cell cycle-regulated proteins (pRb, p34cdc2, and cyclin B1) was observed in alpha-particle or gamma-irradiated human fibroblasts.     

Quantitative diagnosis of stress-induced myocardial ischemia using analysis of contrast echocardiographic parametric perfusion images.

AIMS: Parametric imaging of myocardial perfusion provides useful visual information for the diagnosis of coronary artery disease (CAD). We developed a technique for automated detection of perfusion defects based on quantitative analysis of parametric perfusion images and validated it against coronary angiography. METHODS AND RESULTS: Contrast-enhanced, apical 2-, 3- and 4-chamber images were obtained at rest and with dipyridamole in 34 patients with suspected CAD. Images were analyzed to generate parametric perfusion images of the standard contrast-replenishment model parameters A, beta and A.beta. Each parametric image was divided into six segments, and mean parameter value (MPV) was calculated for each segment. Segmental MPV ratio between stress and rest was defined as a flow reserve index (FRI). Receiver operating characteristics (ROC) analysis was used in a Study group (N=17) to optimize FRI threshold and the minimal number of abnormal segments per vascular territory (LAD and non-LAD), required for automated detection of stress-induced perfusion defects. The optimized detection algorithm was then tested prospectively in the remaining 17 patients (Test group). LAD and non-LAD stenosis >70% was found in 19 and 17 patients, respectively. In the Study group, FRI threshold was: LAD=0.95 and non-LAD=0.68, minimal number of abnormal segments was four and two, correspondingly. Sensitivity, specificity and accuracy in the Test group were: 75%, 67% and 71% in the LAD, and 75%, 75% and 75% in the non-LAD territories. CONCLUSION: Automated quantitative analysis of contrast echocardiographic parametric perfusion images is feasible and may aid in the objective detection of CAD.     

Infections in elderly persons. An altered clinical presentation.

The high prevalence, morbidity, and mortality of infectious diseases in the geriatric population mandates that clinicians caring for older patients become better acquainted and familiar with the special and unique characteristics and features of this common clinical problem. Only through such awareness and understanding will clinical outcomes, functional capacity, and quality of life be improved in the elderly population.     

Identification of a 35 kDa Glycoprotein from Entamoeba histolytica by Sera from Patients with Amoebic Liver Abscess and with Mouse Monoclonal Antibody

In this work, we explored the relevance of a 35 kDa glycoprotein (Gm) of the outer membrane from E. histolytica in the diagnosis of the amoebic liver abscess (ALA) through ELISA and immunoblotting. We were interested in defining the relevance of this antigen in the immune response in patients with amoebic liver abscess and in exploring whether the mouse monoclonal antibody against this 35 kDa glycoprotein recognises the same epitope. We found that 87% of ALA patients had raised antibody levels to Gm antigen, whereas none of the healthy control subjects presented this same increase We also found 90% sensitivity, 100% specificity, 100% positive predictive value, 90% negative predictive value, and 90% prevalence value for this Gm antigen Nonetheless, we did not find any statistically significant differences in the levels of immunoglobulins against Gm, although IgG showed a tendency to increase, probably because we are dealing with a secondary immune response. Using electroimmunotransfer blot assay, we found that sera from ALA patients recognise the 35 kDa Gm protein in the same way as it is recognised by the mouse monoclonal antibody, suggesting that is a relevant molecule for the diagnosis of amebiasis, and eventually could lead to its use as protection against the disease.     

The thoracoscope as diagnostic tool for solid mediastinal masses

Background: Despite the accuracy of percutaneous biopsy of mediastinal masses under CT scan or sonographic control, there is still a need for surgical biopsy because of difficult location or because of insufficiency of the percutaneous biopsy, especially for those tumors requiring an immunological classification. Methods: The thoracoscopic approach to mediastinal masses is an alternative to the usual surgical biopsies performed through thoracotomy, sternotomy, or anterior mediastinotomy. The procedure is performed under general anesthesia and one-lung ventilation. Results: In a series of 47 cases, a histological diagnosis was obtained in 44 cases (93.6%). There was one hemorrhagic complication requiring thoracotomy (2.1%). The mean postoperative duration of stay was 3.2 days. Conclusions: Thoracoscopy is the method of choice in case of failure or contraindication of percutaneous biopsy. There is still a role for mediastinoscopy in treating paratracheal lymph nodes.