Modern processes of palynomorph deposition at lakes of the northern region of the Rio de Janeiro State, Brazil

Palynological analysis of pollen, Pteridophyta spores and algae deposited in the superficial sediments at Lagoa de Cima and Lagoa do Campelo Lakes, located in the north of Rio de Janeiro state, was used to determine the spatial variation of the palynomorphs deposition. A total of 67 pollen types were identified at Lagoa de Cima, with an expressive contribution of regional arboreous taxa, hydrophytes and ruderal plants of the pastureland. The depositional pattern of palynomorphs depends on the fluvial leakage, the proximity of the local sedimentation to the inlet of the Imbé and Urubu Rivers and the bathymetry of lake bottom. The highest concentrations of palynomorphs were observed in the decentralized and less deeper area, without the interference of the northeastern wind. At Lagoa do Campelo, a total of 58 pollen types were identified, among which the majority of the pollen grains came from hydrophytes, with the highest concentrations found along the northeastern shore. The southeastern shore showed high percentages of pollen and spores with degraded exine and mechanical damage, due to the transport through the lake by the currents caused by the wind, confirmed by the depositional trend of damaged palinomorphs along the same direction as the prevailing winds.     

Adverse effects of extra-articular corticosteroid injections: a systematic review

Background  

To estimate the occurrence and type of adverse effects after application of an extra-articular (soft tissue) corticosteroid injection.     

Recurrence of paroxysmal atrial fibrillation after cryoisolation of the pulmonary veins. Is a “redo” procedure using the cryoballoon useful?

Background

Pulmonary vein (PV) isolation with the cryoballoon technique is an effective and safe method to treat patients with paroxysmal atrial fibrillation (AF). However, the optimal treatment strategy for patients with recurrences after this ablation is unclear.

Aims

The aim of this single centre study was to evaluate the efficacy and safety of a “redo” procedure using the cryoballoon in this patient cohort. The secondary study objectives were to determine the rate of reconduction for individual PVs of the patients undergoing “redo” ablation and potential predictors of persistent PV isolation (PVI).

Methods

Between April 2006 and September 2009, all patients with paroxysmal AF recurrences after cryoballoon ablation a “redo” ablation with the cryoballoon was offered. PV conduction was determined and cryoapplications were performed in all reconnected PVs. Every 3 months, 7-day Holter ECG, symptom-driven transtelephonic ECG recordings, and questionnaires were collected for 12 months.

Results

Forty-seven patients underwent “redo” cryoballoon ablation. In all these patients, at least one PV with reconduction was found. Recurrent conduction was documented in 63 % of the left superior PV, 56 % of the left inferior PV, 43 % of the right superior PV, and 56 % of the right inferior PV. In 28 of the 47 patients (60 %), no AF recurrence was detectable during the 12-month follow-up (after 3 months blanking period). Rate of severe complications was low and not significantly different from that of the initial ablations.

Conclusion

“Redo” ablation using cryoballoon technology may be an effective and safe method to treat patients with recurrence of paroxysmal AF after cryoballoon PVI.     

Potential associations between hematogenous complications and bacterial genotype in Staphylococcus aureus infection

BACKGROUND: The impact of bacterial clonality on infections caused by Staphylococcus aureus is unclear. METHODS: Three hundred seventy-nine S. aureus isolates (125 methicillin-resistant S. aureus [MRSA] and 254 methicillin-susceptible S. aureus [MSSA]) were genotyped by spa typing and multilocus sequence typing. For MRSA isolates, the staphylococcal chromosomal cassette mec (SCCmec) element was also typed. Three clinical categories were identified: nasal carriage only (n=118), uncomplicated infection (n=104), and bacteremia with hematogenous complications (n=157). RESULTS: By use of eBURST, 18 clonal complexes (CCs) were found in 371 isolates. Eight CCs accounted for 89% of isolates and occurred in all clinical categories. CC5 (P=.0025) and CC30 (P=.0308) exhibited a significant trend toward more frequent hematogenous complications. Isolates within spa types 2 and 16 showed the same significant trend and grouped within CC5 and CC30, respectively. SCCmec II isolates also showed the same significant trend compared with SCCmec IV; 96% were CC5 or CC30. CONCLUSIONS: Although most S. aureus genotypes exhibited the capacity to cause invasive disease, strains within CC5 and CC30 exhibited a significant trend toward increasing levels of hematogenous complications. Isolates within these CCs were also implicated by use of spa and SCCmec typing. The genetic determinants underlying these findings remain to be demonstrated.     

A young fireman candidate with an abnormal chest x-ray

An 18-year-old, asymptomatic male underwent a routine chest x-ray examination which showed a pathological result. It revealed a characteristic crescent-like shadow in the right lower lung field, resembling a muslim sword (scimitar), responsible for the name of the underlying disease. Scimitar syndrome is a rare congenital malformation with a wide clinical spectrum ranging from asymptomatic to severe disturbances manifesting in childhood. The typical findings are hypoplasia of the right lung with marked mediastinal shift to the right and dextrocardia, reduced right pulmonary artery perfusion with maintained bronchial connection, anomalous arterial supply to the right lower lobe from the aorta and abnormal draining of the enlarged right pulmonary vein into the pulmonary circulation, producing the characteristic radiographic "scimitar sign". The development of right ventricular failure due to long-standing right ventricular overload and recurrent respiratory infections depend on the severity of anatomical abnormalities and functional disorders, sometimes requiring surgical intervention. Nowadays, sophisticated imaging techniques allow precise and rapid diagnosis of these complex abnormalities and their functional implications. The findings for our patient differed from the classic constellation, with a regular emptying of the enlarged right pulmonary vein into the left atrium, leading to a decreased burden on the central haemodynamics. In our very rare case of a scimitar syndrome variant, the functional disorders were negligible.     

Modification of Wright's technique for placement of bilateral crossing C2 translaminar screws: technical note

BACKGROUND CONTEXT: Several relatively new screw techniques have been described that rigidly capture the posterior elements of C2. The previously described procedures of axis fixation are technically demanding and place the vertebral artery at some risk. A novel and less technically demanding technique of obtaining C-2 translaminar screws has been recently described. Although the risk of vertebral artery injury has been essentially eliminated, the authors recognize that neurologic injury from breakthrough of the inner cortex of the lamina by the drill or screw is still a possibility. PURPOSE: Describe and illustrate a modified C2 translaminar technique and review the results of patients who have undergone the surgery. The current modification of the C2 translaminar screw technique was designed to reduce the risk of inadvertent screw placement within the spinal canal. STUDY DESIGN/SETTING: A techniques paper combined with a retrospective clinical review of patients undergoing the surgery. PATIENT SAMPLE: Patients undergoing posterior instrumented fusion surgery of the cervical spine, which incorporates C2 posterior elements using the translaminar technique. OUTCOME MEASURES: Radiographic analysis of the fusion construct incorporating the C2 translaminar screws. METHODS: We have modified the previously described technique of C-2 translaminar screw placement with the addition of "exit" cortical windows to assure bicortical, intralaminar screw placement. RESULTS: The results of the first six patients with an average follow-up of 12 months demonstrated this method to be safe and effective in fixating the axis. CONCLUSIONS: We have made a simple modification of Wright's elegant technique with the addition of "exit" windows at the facet-laminar junctions. This gives us the assurance that the C2 screw has not entered the spinal canal by directly visualizing the tip of the screw exiting the outer cortices of the lamina before leaving the operating room.     

Zwitterionic self-assembly of L-methionine nanogratings on the Ag(111) surface

The engineering of complex architectures from functional molecules on surfaces provides new pathways to control matter at the nanoscale. In this article, we present a combined study addressing the self-assembly of the amino acid L-methionine on Ag(111). Scanning tunneling microscopy data reveal spontaneous ordering in extended molecular chains oriented along high-symmetry substrate directions. At intermediate coverages, regular biomolecular gratings evolve whose periodicity can be tuned at the nanometer scale by varying the methionine surface concentration. Their characteristics and stability were confirmed by helium atomic scattering. X-ray photoemission spectroscopy and high-resolution scanning tunneling microscopy data reveal that the L-methionine chaining is mediated by zwitterionic coupling, accounting for both lateral links and molecular dimerization. This methionine molecular recognition scheme is reminiscent of sheet structures in amino acid crystals and was corroborated by molecular mechanics calculations. Our findings suggest that zwitterionic assembly of amino acids represents a general construction motif to achieve biomolecular nanoarchitectures on surfaces.     

Sequential structure of neocortical spontaneous activity in vivo

Even in the absence of sensory stimulation, the neocortex shows complex spontaneous activity patterns, often consisting of alternating "DOWN" states of generalized neural silence and "UP" states of massive, persistent network activity. To investigate how this spontaneous activity propagates through neuronal assemblies in vivo, we simultaneously recorded populations of 50-200 cortical neurons in layer V of anesthetized and awake rats. Each neuron displayed a virtually unique spike pattern during UP states, with diversity seen amongst both putative pyramidal cells and interneurons, reflecting a complex but stereotypically organized sequential spread of activation through local cortical networks. Spike timing was most precise during the first approximately 100 ms after UP state onset, and decayed as UP states progressed. A subset of UP states propagated as traveling waves, but waves passing a given point in either direction initiated similar local sequences, suggesting local networks as the substrate of sequential firing patterns. A search for repeating motifs indicated that their occurrence and structure was predictable from neurons' individual latencies to UP state onset. We suggest that these stereotyped patterns arise from the interplay of intrinsic cellular conductances and local circuit properties.     

Gas gangrene of the abdominal wall due to underlying GI pathology: seven cases

OBJECTIVE: Gas gangrene of the abdominal wall is a rare clinical occurrence with high rates of morbidity and mortality. The primary source of the infection is often unknown. To analyze the primary underlying intestinal etiologies and diagnostic approaches of gas gangrene of the abdominal wall, and to highlight specific treatment problems, particularly that of constructing a colostomy exteriorized through a massively infected abdominal wall. PATIENTS AND METHODS: Seven cases of abdominal wall gas gangrene due to a gastrointestinal etiology were identified. (Cases arising from proctologic sources or related to recent abdominal surgery were excluded.) During the same period, 39 other patients presenting with abdominal wall gangrene from non-intestinal sources were treated. RESULTS: The etiologies were: perforated sigmoid diverticulitis (n=2), perforated appendicitis (n=1), acute pancreatitis with associated cecal perforation (n=1), and perforated colorectal cancer (n=3). Four of the seven patients died despite treatment (mortality of 57%). CONCLUSION: The clinical presentations of these seven cases demonstrate that a GI source must be suspected whenever a patient presents with abdominal wall gas gangrene, even when there are no specific GI symptoms. Imaging, particularly with CT scan, is essential both to visualize the extent of tissue necrosis and to reveal underlying primary GI pathology. This optimizes the surgical approach both by allowing for complete debridement and drainage of infected tissue, and by focussing the intervention on correction of the underlying primary GI source of infection.     

Limb-girdle muscular dystrophy in the Netherlands: gene defect identified in half the families

Pheno- and genotype correlation is attempted in a Dutch cross-sectional study on limb- girdle muscular dystrophy. Sarcoglycans, caveolin-3, calpain-3, and dysferlin were analyzed on muscle tissue. Mutation analysis of the calpain-3, caveolin-3, and fukutin-related protein gene was executed in successive order for all samples. In 51% of all families a classifying diagnosis was made. Several new mutations in LGMD2A, B, and C patients have been found in this population.