Retinal detachment in eyes undergoing pars plana vitrectomy for removal of retained lens fragments

PURPOSE: To investigate the incidence and outcomes of retinal detachment (RD) associated with retained lens fragments removed by pars plana vitrectomy (PPV). DESIGN: Retrospective, noncomparative, interventional consecutive case series. PARTICIPANTS: All patients who underwent PPV for retained lens material after cataract surgery at Bascom Palmer Eye Institute between January 1, 1990, and December 31, 2001. METHODS: Demographic and clinical data were extracted from patients' medical records. MAIN OUTCOME MEASURES: Incidence of retinal detachment, reattachment rate, and visual acuity outcome. RESULTS: RD occurred in 44 of 343 (12.8%) patients, including 25 (7.3%) before or during PPV and 19 (5.5%) after PPV. The RD was macula-on in 22 of 44 (50%) patients and macula-off in 22 of 44 (50%) patients. The RD was associated with a giant retinal tear in 7 of 44 (15.9%) patients, limited suprachoroidal hemorrhage in 3 of 44 (6.8%) patients, and endophthalmitis in 4 of 44 (9.1%) patients. Retinal reattachment was achieved in 40 of 44 (90.9%) patients; 14 of 44 (31.8%) patients underwent one or more additional procedures for recurrent detachment. Final visual acuity in the patients in this series was >/=20/40 in 8 of 44 (18%), 20/50 to 20/100 in 13 of 44 (30%), 20/200 to 5/200 in 13 of 44 (30%), and <5/200 in 10 of 44 (23%). In the 36 patients with vision less than 20/40, the primary causes of decreased vision were attributed to prior history of RD in 8 of 36 (22.2%), corneal edema in 7 of 36 (19.4%), cystoid macular edema in 5 of 36 (13.9%), persistent retinal detachment in 4/36 (11.1%), preexisting primary open-angle glaucoma in 4 of 36 (11.1%), age-related macular degeneration in 3 of 36 (8.3%), epiretinal membrane in 2 of 36 (5.5%), macular hole in 1 of 36 (2.7%), optic atrophy in 1 of 36 (2.7%), and irregular astigmatism in 1 of 36 (2.7%) patients. CONCLUSIONS: RD is a frequent complication in eyes undergoing PPV for removal of retained lens fragments. Despite favorable retinal reattachment rates, visual acuity outcomes are often poor in these eyes and are associated with other comorbidities such as corneal edema and cystoid macular edema. Poor initial visual acuity and the presence of a retinal tear at the time of PPV were associated with a higher rate of RD after PPV.     

Interaction of human salivary mucin MG2, its recombinant N-terminal region and a synthetic peptide with Actinobacillus actinomycetemcomitans

The antimicrobial properties of human salivary mucin MG2 against the periodontal pathogen, Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans), were investigated using purified MG2, rNMUC7 (a recombinant polypeptide containing residue 1-144 of MG2) and synthetic peptides PEP1 (residue 1-17) and PEP2 (residue 47-63). MG2 and rNMUC7 bound to A. actinomycetemcomitans strains SUNY75, SUNY465, SUNY523, 652 and JP2 in a liquid phase binding assay. The bactericidal activities of rNMUC7, PEP1 and PEP2 against A. actinomycetemcomitans SUNY523 were examined in a colony forming unit killing assay. The LD50 for rNMUC7 was 9 microM, for PEP2 was 20 microM and PEP1 did not exhibit bactericidal activity. The primary structure of these polypeptides was analyzed and a direct relationship between net positive charge and bactericidal activity was found. Screening of saliva samples from 60 individuals on Western blots probed with an anti-MG2 antibody against PEP2 revealed that a 20 kDa MG2 fragment was present in 66% of subjects and that this fragment was not present in glandular secretions. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry of tryptic peptides derived from the 20 kDa fragment confirmed that this fragment contained a portion of the amino terminal region of MG2. The present study showed that the N-terminal region of MG2 and a subdomain within this region are microbicidal against A. actinomycetemcomitans and that a 20 kDa fragment of MG2 occurs in whole saliva. This suggests that cleavage of MG2 in vivo may produce fragments with microbicidal properties and that this may represent a novel mechanism of host defense.     

A review and update on cholangiocarcinoma

Cholangiocarcinoma is a malignant neoplasm arising from the biliary epithelium that was first described by Durand-Fardel in 1840. Today, it continues to defy diagnosis and treatment. It is difficult to diagnose in part because of its relative rarity, and because it is clinically silent until it becomes advanced disease with obstructive symptoms. The worldwide incidence of cholangiocarcinoma has risen over the past three decades. There is marked geographic variability in the prevalence of this disease, due in large part to regional environmental risk factors. Surgical resection remains the only curative treatment, and high priorities are improving diagnostic methods, and clinical staging for resection once the disease is suspected. A recent trend towards aggressive surgical management has improved outcomes. Chemotherapy, palliative stenting, and radiation are reserved for patients who are not resectable, those with recurrence after surgery, and those who decline surgical intervention. Recent trials using combination systemic chemotherapy and neoadjuvant chemoradiation are promising, but require further study. Over the past five years, several important studies have yielded new insights into the molecular mechanisms of cholangiocarcinoma tumorigenesis. In this review we discuss epidemiology, etiologic factors, molecular pathogenesis, diagnosis, staging, and treatment of cholangiocarcinoma. Particular focus is on recent studies into the cellular and molecular pathogenesis of the disease, recent chemotherapy trials, and newer methods of staging and screening for this devastating malignancy.     

Primary orbital mesenchymal chondrosarcoma: a case report and literature review

Background Mesenchymal chondrosarcoma (MC) is a subtype of chondrosarcoma, with an incidence varying from 1 to 8% of all chondrosarcomas. It is an aggressive neoplasm with a high tendency for late recurrence and occasional delayed distant metastasis. Orbital MC is very rare, and only approximately 30 cases have been described in the literature. We describe here one case of primary orbital MC. Case report A 14-year-old boy without a past medical history presented with a 1-month history of progressive proptosis on the right eye. Computed tomography (CT) scans of the orbit revealed a right intraconic lesion, with areas of calcification. The lesion was excised. Histopathological analysis revealed that the tumor had a biphasic pattern, showing a combination of small cell malignancy and well-differentiated cartilage. Immunohistochemistry examination revealed a diffuse membrane expression of CD99 on the small cell malignancy; S-100 was positive only within the cartilage component. The patient received chemotherapy, and no metastatic disease was found at the 2-month follow-up. Conclusion Although rare, MC should be considered in the differential diagnosis of a well-circumscribed orbital lesion in young adults, especially when CT scans reveal areas of calcification within the tumor.     

Prenatal stress alters the behavior and dendritic morphology of the medial orbitofrontal cortex in mouse offspring during lactation

Several preclinical and clinical studies have shown that prenatal stress alters neuronal dendritic development in the prefrontal cortex, together with behavioral disturbances (anxiety). Nevertheless, neither whether these alterations are present during the lactation period, nor whether such findings may reflect the onset of anxiety disorders observed in childhood and adulthood has been studied. The central aim of the present study was to determine the effects of prenatal stress on the neuronal development and behavior of mice offspring during lactation (postnatal days 14 and 21). We studied 24 CF-1 male mice, grouped as follows: (i) control P14 (n = 6), (ii) stressed P14 (n = 6), (iii) control P21 (n = 6) and (iv) stressed P21 (n = 6). On the corresponding days, animals were evaluated with the open field test and sacrificed. Their brains were then stained in Golgi-Cox solution for 30 days. The morphological analysis dealt with the study of 96 pyramidal neurons. The results showed, first, that prenatal stress resulted in a significant (i) decrease in the apical dendritic length of pyramidal neurons in the orbitofrontal cortex at postnatal day 14, (ii) increase in the apical dendritic length of pyramidal neurons in the orbitofrontal cortex at postnatal day 21, and (iii) reduction in exploratory behavior at postnatal day 14 and 21.     

Stress-induced cross-sensitization to amphetamine is related to changes in the dopaminergic system

Repeated stress engenders behavioral sensitization. The mesolimbic dopamine system is critically involved in drug-induced behavioral sensitization. In the present study we examined the differences between adolescent and adult rats in stress-induced behavioral sensitization to amphetamine and changes in dopamine (DA) and its metabolite levels in the mesolimbic system. Adolescent or adult rats were restrained for 2 h, once a day, for 7 days. Three days after the last exposure to stress, the animals were challenged with saline or amphetamine (1.0 mg/kg i.p.) and amphetamine-induced locomotion was recorded for 40 min. Immediately after the behavioral tests, rats were decapitated and the nucleus accumbens (NAcc), ventral tegmental area (VTA) and amygdala (AM) were removed to measure tissue levels of DA and its metabolites by HPLC. Exposure to repeated restraint stress promoted behavioral sensitization to amphetamine in both adult and adolescent rats. In adult rats, amphetamine administration increased DA levels in both the stress and control groups in the NAcc and VTA. In adolescent rats, amphetamine increased DA levels in the NAcc in rats exposed to stress. Furthermore, in the AM of adolescent rats in the control group, amphetamine increased the DA levels; however, amphetamine reduced this neurotransmitter in the rats that were exposed to stress. No alteration was observed in the dopamine metabolite levels. Therefore, stress promoted behavioral sensitization to amphetamine and this may be related to changes in DA levels in the mesolimbic system. These changes appear to be dependent on ontogeny.     

Differential susceptibility following beta-amyloid peptide-(1-40) administration in C57BL/6 and Swiss albino mice: Evidence for a dissociation between cognitive deficits and the glutathione system response

Considerable evidence supports the role of oxidative stress in the pathogenesis of Alzheimer's disease (AD). Previous studies suggest that the central nervous system (CNS) administration of beta-amyloid peptide, the major constituent of senile plaque in AD, induces oxidative stress in rodents which may contribute to the learning and memory deficits verified in the beta-amyloid model of AD. In the present study, we compared the effects of a single intracerebroventricular (i.c.v.) injection of aggregated beta-amyloid peptide-(1-40) (Abeta(1-40)) (400pmol/mouse) on spatial learning and memory performance, synaptic density and the glutathione (GSH)-dependent antioxidant status in adult male C57BL/6 and Swiss albino mice. Seven days after Abeta(1-40) administration, C57BL/6 and Swiss mice presented similar spatial learning and memory impairments, as evaluated in the water maze task, although these impairments were not found in Abeta(40-1)-treated mice. Moreover, a similar decline of synaptophysin levels was observed in the hippocampus (HC) and prefrontal cortex (PFC) of both Swiss and C57BL/6 mice treated with Abeta(1-40), which suggests synaptic loss. C57BL/6 mice presented lower levels of glutathione-related antioxidant defences (total glutathione (GSH-t) levels, glutathione peroxidase (GPx) and glutathione reductase (GR) activity) in the HC and PFC in comparison to Swiss mice. Despite the reduced basal GSH-dependent antioxidant defences observed in C57BL/6 mice, Abeta(1-40) administration induced significant alterations in the brain antioxidant parameters only in Swiss mice, decreasing GSH-t levels and increasing GPx and GR activity in the HC and PFC 24h after treatment. These results indicate strain differences in the susceptibility to Abeta(1-40)-induced changes in the GSH-dependent antioxidant defences in mice, which should be taken into account in further studies using the Abeta model of AD in mice. In addition, the present findings suggest that the spatial learning and memory deficits induced by beta-amyloid peptides in rodents may not be entirely related to glutathione-dependent antioxidant response.     

Use of checkerboard DNA–DNA hybridization to evaluate the internal contamination of dental implants and comparison of bacterial leakage with cast or pre-machined abutments

Aims: To evaluate the checkerboard DNA–DNA hybridization method for detection and quantitation of bacteria from the internal parts of dental implants and to compare bacterial leakage from implants connected either to cast or to pre-machined abutments.
Materials and methods: Nine plastic abutments cast in a Ni–Cr alloy and nine pre-machined Co–Cr alloy abutments with plastic sleeves cast in Ni–Cr were connected to Branemark-compatible implants. A group of nine implants was used as control. The implants were inoculated with 3 μl of a solution containing 10⁸ cells/ml of Streptococcus sobrinus . Bacterial samples were immediately collected from the control implants while assemblies were completely immersed in 5 ml of sterile Tripty Soy Broth (TSB) medium. After 14 days of anaerobic incubation, occurrence of leakage at the implant–abutment interface was evaluated by assessing contamination of the TSB medium. Internal contamination of the implants was evaluated with the checkerboard DNA–DNA hybridization method.
Results: DNA–DNA hybridization was sensitive enough to detect and quantify the microorganism from the internal parts of the implants. No differences in leakage and in internal contamination were found between cast and pre-machined abutments. Bacterial scores in the control group were significantly higher than in the other groups ( P <0.05).
Conclusion: Bacterial leakage through the implant–abutment interface does not significantly differ when cast or pre-machined abutments are used. The checkerboard DNA–DNA hybridization technique is suitable for the evaluation of the internal contamination of dental implants although further studies are necessary to validate the use of computational methods for the improvement of the test accuracy.