Recurrent cerebellar ischemic infarctions and stereotyped peri-ictal sympathetic responses in a near-SUDEP patient with cardiovascular risk factors.

We report a 60-year-old woman who presented to the emergency department after experiencing a witnessed unknown onset bilateral tonic clonic seizure (GTCS) that culminated in cardiac arrest. A neurology consultant uncovered a years-long history of frequent episodic staring followed by confusion and expressive aphasia, which strongly suggested that she suffered from epilepsy. Thus, her cardiac arrest and subsequent resuscitation met criteria for a near-sudden unexpected death in epilepsy (SUDEP) diagnosis. Serial bloodwork demonstrated transient troponin I elevations and leukocytoses, while a brain MRI revealed global cerebral anoxic injury and a small acute right cerebellar ischemic infarction. A review of her medical record uncovered a hospitalization sixteen months earlier for a likely GTCS whose workup showed similar troponin I elevations and leukocytoses, and surprisingly, a different small acute right cerebellar ischemic infarction in the same vascular territory. To our knowledge, this is the first report of subcortical ischemic infarctions occurring concurrently with GTCSs in a near-SUDEP patient. Aside from illustrating the key role of inpatient neurologists in the diagnosis of near-SUDEP, this manuscript discusses the potential significance of postictal ischemic infarctions, transient asymptomatic troponin elevations, and transient non-infectious leukocytoses in epilepsy patients with cardiovascular risk factors.

Ib-M6 Antimicrobial Peptide: Antibacterial Activity against Clinical Isolates of Escherichia coli and Molecular Docking.

The Ib-M6 peptide has antibacterial activity against non-pathogenic Escherichia coli K-12 strain. The first part of this study determines the antibacterial activity of Ib-M6 against fourteen pathogenic strains of E. coli O157:H7. Susceptibility assay showed that Ib-M6 had values of Minimum Inhibitory Concentration (MIC) lower than streptomycin, used as a reference antibiotic. Moreover, to predict the possible interaction between Ib-M6 and outer membrane components of E. coli, we used molecular docking simulations where FhuA protein and its complex with Lipopolysaccharide (LPS-FhuA) were used as targets of the peptide. FhuA/Ib-M6 complexes had energy values between -39.5 and -40.5 Rosetta Energy Units (REU) and only one hydrogen bond. In contrast, complexes between LPS-FhuA and Ib-M6 displayed energy values between -25.6 and -40.6 REU, and the presence of five possible hydrogen bonds. Hence, the antimicrobial activity of Ib-M6 peptide shown in the experimental assays could be caused by its interaction with the outer membrane of E. coli.

Biopolymeric pellets of polyvinyl alcohol and alginate for the encapsulation of Ib-M6 peptide and its antimicrobial activity against E. coli.

The encapsulation of Ib-M6 antibacterial peptide in pellets of polyvinyl alcohol (PVA) and polyvinyl alcohol-alginate (PVA-Alg) matrices was carried out in order to explore its controlled release and activity against Escherichia coli K-12. The pellets were obtained by combined ice segregation induced self-assembly (ISISA) and freezing-thawing methods and their microstructure was studied by scanning electron microscopy. Bromothymol blue was used as a model compound to study the transport mechanisms and release from pellets. The results show that there is a significant effect of the total concentration of PVA precursor solutions, the mass ratio of PVA of different molecular weights and the addition of alginate on the microstructure and transport properties of pellets. The antibacterial activity of Ib-M6 against Escherichia coli K-12 was not affected by the encapsulation in PVA pellets. However, the release of Ib-M6 from PVA-Alg pellets was not possible, probably due to the electrostatic interaction of positively charged Ib-M6 and negatively alginate structure. Nonetheless, the controlled release of Ib-M6 from polymeric matrices can be fitting by modifying parameters such as the concentration and type of polymer precursors.

Surface diffusion and low vibrational motion with interacting adsorbates: a shot noise description.

Here, an approach in terms of shot noise is proposed to study and characterize surface diffusion and low vibrational motion when having interacting adsorbates on surfaces. In what we call statistical limit, that is, at long times and high number of collisions, one expects that diffusing particles display an essential Markovian behavior. Accordingly, the action of the pairwise potentials accounting for particle-particle collisions is equivalent to considering a shot noise acting on a single particle. We call this approach the interacting single adsorbate approximation, which gathers three important advantages: (i) the dynamics underlying surface diffusion and low vibrational motion can be easily understood in terms of relatively simple stochastic processes; (ii) from our model, appropriate (and well justified) working formulas are easily obtained, which explain the results arising from more complicated (but commonly used) molecular dynamics simulations within the Langevin formulation; and (iii), at the same time, it is less demanding computationally than the latter type of calculations. In order to illustrate the application of this model, numerical results are presented. Specially, our model reproduces the experimental observation regarding the broadening of the quasielastic peak ruling surface diffusion.

Quasi-elastic peak lineshapes in adsorbate diffusion on nearly flat surfaces at low coverages: the motional narrowing effect in Xe on Pt(111).

Quasi-elastic helium atom scattering measurements have provided clear evidence for a two-dimensional free gas of Xe atoms on Pt(111) at low coverages. Increasing the friction due to the surface, a gradual change of the shape of the quasi-elastic peak is predicted and analysed for this system in terms of the so-called motional narrowing effect. The type of analysis presented here for the quasi-elastic peak should be prior to any deconvolution procedure carried out in order to better extract information from the process, e.g. diffusion coefficients and jump distributions. Moreover, this analysis also provides conditions for the free gas regime different to those reported earlier.

Right ventricular asynergy during dobutamine-atropine echocardiography.

OBJECTIVES: We sought to analyze right ventricular contractility during dobutamine infusion in patients with right coronary artery disease and to elucidate whether the development of right ventricular asynergy aids in characterizing a right coronary artery stenosis. BACKGROUND: Clinical investigations are emphasizing the importance of right ventricular function in patients with coronary artery disease. Thus, prognosis of patients with inferior myocardial infarction is influenced by right ventricular function. This study describes the echocardiographic and electrocardiographic findings during dobutamine-atropine echocardiography in patients with right coronary artery disease. METHODS: We studied 31 patients with isolated right coronary artery disease and no previous myocardial infarction. Six patients with poor acoustic window were excluded (feasibility 80%). The remaining 25 patients underwent dobutamine-atropine echocardiography. A right coronary artery stenosis located before the origin of the right ventricular branches was considered proximal; otherwise, it was considered distal. RESULTS: Right ventricular asynergy during dobutamine-atropine testing developed in 17 patients (sensitivity 68%); 14 had proximal and 3 had distal right coronary artery disease. The following segments were involved: inferior (n = 17), lateral (n = 5) and outflow tract (n = 1). No patient showed anterior asynergy. All 17 patients had left ventricular asynergy as well. Ischemia-free time was 10.7 +/- 6.2 (mean +/- SD) min for the right ventricle and 8.9 +/- 5.2 min for the left ventricle (p < 0.05). Ischemic ST changes were recorded in 15 patients (in standard leads in 14 and in right precordial leads in 8). All patients with right precordial changes showed ST elevation and had right ventricular asynergy (sensitivity and specificity for right ventricular asynergy 47% and 100%, respectively). A control group of 25 patients with no right coronary artery disease (5 with no disease, 15 with left anterior descending and 5 with left circumflex coronary artery disease) underwent dobutamine echocardiography. Right ventricular asynergy developed in two patients with left anterior descending artery stenosis (specificity 92%); in both, the anterior wall was affected. CONCLUSIONS: Echocardiography during dobutamine infusion is a reliable technique for assessing right ventricular dysfunction in patients with right coronary artery disease. Right ventricular contractility can be assessed during dobutamine echocardiography in selected patients.

Clinical course, microbiologic profile, and diagnosis of periannular complications in prosthetic valve endocarditis.

Whether periannular extension of prosthetic valve endocarditis (abscesses, pseudoaneurysms, fistulas) is related to the etiologic agent, the clinical course and the prognosis is still unknown. Likewise, transesophageal echocardiographic accuracy in detecting periannular complications in prosthetic recipients remains unsettled. We retrospectively analyzed data from 87 patients with anatomically proven prosthetic valve endocarditis who underwent a transesophageal echocardiographic examination. Periannular complications (30 abscesses, 18 pseudoaneurysms, 8 fistulas; 8 with >1) were found in 46 patients; results were compared with the remaining 41 without complications. Transesophageal echocardiography correctly identified 27 abscesses (90%) and all pseudoaneurysms and fistulas. One diagnosis of pseudoaneurysm by echocardiography was not found at surgery. No statistical differences were found regarding age, sex, type of prosthesis (mechanical vs biologic), and etiologic agent. Periannular complications were more frequent in aortic location (70% vs 20% in mitral position; p <0.001) and in early (within 6 months after surgery) endocarditis (63% vs 38% in late endocarditis; p = 0.04). The same percentage of patients from both groups underwent surgery (98% with and 90% without complications). At discharge, 62% and 67% of patients were alive, respectively. Thus, periannular complications in prosthetic valve endocarditis are more frequent in aortic location and within 6 months after surgery. Neither the type of prosthesis nor the etiologic agent are related to the presence of periannular complications. Short-term prognosis in patients who underwent surgery is not affected by the presence of periannular complications.

Maximizing productivity in an immobilized cell reactor.

A vertical immobilized cell reactor employing Saccharomyces cerevisiae cross-linked to a gelatin support with glutaraldehyde has proven to be an effective system to achieve high cell concentrations and high dilution rates. The reactor is very stable over long periods of time, during which the cell concentration increases continuously without achieving steady state. Therefore, periodic regeneration by gas purging is required to remove excess biomass from the interstitial spaces. The glucose concentrations along the reactor follow an exponential profile when plotted as a function of the true residence time. Such profiles are a function of the initial glucose concentration fed to the system. The overall productivity of the reactor is a function of the flow rate and the inlet glucose concentration. For a 99% conversion, the maximum overall productivity is obtained at a substrate concentration of between 15% and 20%. Theoretical cell profiles were obtained and they indicate that mass transfer is promoted at high substrate concentrations and flow rates. The performance of a variety of packing materials having different shapes and materials of construction were compared in a vertical packed bed immobilized cell reactor. With other parameters being constant, the performance of the reactor is dominated by the quantity of cells present. The packing that has the highest surface area per volume of bed yields the most extensive monolayer and gives faster reactor start-up. Packing materials having high biomass loading rates are desirable at prolonged operating periods when growth beyond the monolayer occurs. Ultimately, the packing with the highest initial porosity would be capable of loading the highest cell volume, provided that sufficient interstitial spaces were provided for cell entrapment. When the immobilized cell reactor is operated in the horizontal position, CO2 holdup is decreased, as is evidenced by an increase in liquid holdup. However, the horizontal and vertical reactors showed almost identical substrate profiles at constant cell densities. In addition, under prolonged operation, the performance of the horizontal reactor decayed after several days, while the vertical reactor remained stable for over 40 days. The improved operation of this type of column in the vertical position is attributed to the necessary promotion of mass transfer with CO2 evolution and better liquid distribution. The addition of fatty acids to the media for an ICR results in limiting growth and increasing productivity. Overgrowth can be minimized, thus allowing longer periods of operation without regeneration.(ABSTRACT TRUNCATED AT 400 WORDS)

Open mitral commissurotomy: fourteen- to eighteen-year follow-up clinical study.

From May 1974 to December 1978, 159 patients with mitral stenosis underwent open mitral commissurotomy at our institution. Follow-up data were complete in 96.8%, with a mean follow-up of 13.7 years (range, 14 to 18 years). Preoperatively, most patients (n = 94) were in functional class III or IV. Valve calcification was found in 18 patients (11.3%), left atrial thrombosis was found in 21 (13.2%), and the subvalvular apparatus was affected in 105 (66%). When a residual insufficiency was detected during the operation, a mitral annuloplasty was performed (n = 43). There was one hospital death (0.6%) and 15 late deaths (9.5%). Actuarial survival at 15-year and 18-year follow-up is 89.4% +/- 3% and 75.2% +/- 10.8%. Fifteen patients (9.7%) had a thromboembolic episode 1 to 189 months after operation (mean, 104.3 months). Eleven patients (7%) required reoperation 3 to 183 months after operation (mean, 110.1 months). Freedom from reoperation at 18-year follow-up was 91.9% +/- 2.7%. Event-free actuarial survival at 15-year and 18-year follow-up was 73.4% +/- 4.2% and 54.3% +/- 10.5%. Most patients (n = 131) are in class I or II. Open mitral commissurotomy represents a safe surgical alternative for treating mitral stenosis, allowing a complete removal of atrial thrombosis if present. This long-term follow-up clinical study encourages us to persist in this successful surgical repair of mitral stenosis.

Heart valve replacement with the Hancock bioprosthesis: a 6-year review.

All patients who had a mitral or aortic Hancock valve replacement between June, 1974, and June, 1979, were reviewed. A total of 734 bioprostheses were implanted in 632 patients: 291 had mitral (MVR), 239 had aortic (AVR), and 102 had both mitral and aortic valve replacement (MVR + AVR). In 228 patients, an associated surgical procedure was necessary. It involved conservative valve operation in 205 of them. The hospital mortality was 9.6% (28) for MVR (11.5% with associated operation), 4.6% (11) for AVR (8.7% with associated operation), and 13.7% (14) for MVR + AVR (13.0% with associated operation). The follow-up period was between 1 and 6 years with a total follow-up of 934.6, 714.6, and 288.3 patient-years for MVR, AVR and MVR + AVR, respectively. The late mortality was 0.96% (9), 1.53% (11), and 2.08% (6) per patient-year for MVR, AVR, and MVR + AVR, respectively. The thromboembolic rate was 1.49%, 0.14%, and 2.08% per patient-year for MVR, AVR, and MVR + AVR, respectively. There were twelve valve failure (six wer due to rupture; four, thrombosis; one, insufficiency because of intrinsic failure; and one, stenosis without evident cause at reoperation). This represents a failure rate of 0.53%, 0.13%, and 2.08% per patient-year for MVR, AVR, and MVR + AVR, respectively. These results encourage us to continue our routine use of the glutaraldehyde xenografts as the safest valve substitute at present.

Open mitral commissurotomy.

We analyzed the results obtained in 163 consecutive patients with "pure" mitral stenosis who underwent operation by the open approach exclusively. Calcification was found in the mitral valve leaflets in 11% of the patients and left atrial thrombus, in 13.2%. A statistically significant relationship was discovered between history of previous systemic embolism and cardiac rhythm (p less than 0.005). The subvalvular apparatus was affected in 66.6% of patients; most of them were in New York Heart Association Functional Class III (p less than 0.005). The frequency with which annuloplasty had to be performed because of mitral insufficiency after commissurotomy was statistically higher (p less than 0.025) among patients in Functional Class III. Early mortality was 1.2% and late mortality, 0.2% per patient-year. Two patients required late reoperation (0.4% per patient-year). One was in Functional Class III and the other, Functional Class IV before the first operation. Three patients sustained a late systemic embolism (0.6% per patient-year). All survivors but 1 are in Functional Class I (84.4%) or II (14.9%).

Excitatory transmitters, ventral root potentials and [K+]o in the isolated frog leg-spinal cord preparation.

Motoneuron depolarizations and changes in [K+]o were studied in the isolated frog spinal cord in response to non-nociceptive (touch/pressure) and nociceptive (acetic acid, heat, pinch) stimulation of the skin of the leg. Kynurenate, APV (D(-)-2-amino-5-phosphonovalerate), and 1.0 mM Mg2+ blocked or substantially reduced responses produced by all types of stimuli. Spantide was minimally effective in reducing nociceptive responses and had insignificant effects on responses to innocuous stimuli. These observations are consistent with the notion that excitatory amino acids activating both N-methyl-D-aspartate (NMDA) and non-NMDA receptors participate in the reflex responses to cutaneous stimuli in the frog spinal cord.

Antibodies to hepatitis C virus: a cross-sectional study in patients attending a trauma unit or admitted to hospital for elective surgery.

OBJECTIVE: To assess the prevalence of hepatitis C virus (HCV) antibodies in patients attending a trauma unit or admitted to hospital for elective surgery, and to identify risk factors for acquiring HCV infection. DESIGN: A cross-sectional study. SETTING: The emergency room of a Department of Orthopaedic Surgery and a hospital for elective (non-digestive) surgery. PATIENTS: A study population of 1824 subjects (mean age 40.1 +/- 18.1 years) and sera from a control group of 4703 blood donors giving their first donation. INTERVENTIONS: Serum samples were screened for HCV antibodies by second-generation enzyme-linked immunosorbent assays and recombinant immunoblot assays. MAIN OUTCOME MEASURES: HCV serostatus and the relationship between anti-HCV-positivity and age, intravenous drug use, tattoos, blood transfusion, a history of hepatitis and exposure to a contact who had had hepatitis. RESULTS: The overall prevalence of anti-HCV antibodies was 2.85% in the study population and 0.5% among blood donors (chi 2 = 64.5; P < 0.0001). Anti-HCV-positivity was more common in men (3.8 versus 1.9%; P < 0.05) and in subjects with history of hepatitis (13.5 versus 2.0%; P < 0.001), exposure to a contact who had had hepatitis (12.5 versus 1.9%; P < 0.001), blood transfusion (7.8 versus 2.3%; P < 0.001), tattoos (36 versus 2.4%; P < 0.001) and intravenous drug use (85.7 versus 1.9%; P < 0.001). However, one third of subjects had no risk factors for HCV infection. The logistic regression analysis confirmed a statistically significant association (P < 0.05) between anti-HCV-positivity and intravenous drug use, tattoos, blood transfusion, a history of hepatitis and exposure to a contact who had had hepatitis. CONCLUSIONS: These results show almost a five-fold higher prevalence of anti-HCV among patients attending a trauma unit or admitted to hospital for elective surgery than among blood donors.

Timing of postpartum tubal sterilization using the Filshie clips: an analysis of data from two developing-country centers.

Two-hundred-ninety-seven women at a Panamanian center and 148 women at a Philippine center had their tubal sterilization performed during their postpartum hospital stay after an uncomplicated vaginal delivery of a live birth. The sterilizations were all performed with the use of the Filshie clip via minilaparotomy. The timing of the sterilization varied from two hours to six days after delivery. At each of the two centers, women sterilized within 48 hours after delivery were compared with those sterilized at 49 or more hours with respect to surgical difficulties, tubal injuries, complications/complaints, technical failures and lengths of hospitalization after sterilization and before discharge. The one-year gross cumulative pregnancy rates were also compared. No significant differences were detected in any of the above outcome variables between the two timing groups at each center. While the data suggest that tubal sterilizations by the Filshie clip performed two to six days following childbirth are as safe and effective as those performed within 48 hours of delivery, further studies are urged.

PIP: 297 women at a Panamanian center and 148 women at a Philippine center had their tubal sterilizations performed during their postpartum hospital stays after uncomplicated vaginal deliveries of livebirths. The sterilizations were all performed with the use of the Filshie clip via minilaparotomy. The timing of the sterilizations varied from 2 hours-6 days after delivery. At each of the 2 centers, women sterilized within 48 hours after delivery were compared with those sterilized at 49 or more hours with respect to surgical difficulties, tubal injuries, complications/complaints, technical failures, and lengths of hospitalization after sterilizations and prior to discharge. The 1 year grossed cumulative pregnancy rates were also compared. No significant differences were detected in any of the above outcome variables between the 2 timing groups at each center. While the data suggest that tubal sterilizations by Filshie clip performed between 2-6 days postpartum are as safe and effective as those performed within 48 hours of delivery, further studies are necessary.

Successful treatment of vasospastic angina with a coronary stent.

Calcium antagonists are the treatment of choice in vasospasm angina when no stenosis or mild stenosis are present. We present a case in which ergonovine echocardiography showed vasospasm of the right coronary artery despite optimal medical treatment. Stenting of a mild stenosis in that artery successfully controlled vasospasm and a pre-discharge ergonovine echocardiographic test was negative. The patient remains asymptomatic one year after stenting.

Candida arthritis in an immunocompetent patient without predisposing factors.

Candida arthritis is infrequent in patients who are not intravenous drug users. We describe a patient who was not an intravenous drug user and without other predisposing factors who developed knee arthritis caused by Candida albicans. We believe that this is the first report of such a case.

Pulmonary haemorrhage and focal necrotizing glomerulonephritis in a case of systemic sclerosis.

We report a case of a 53-year-old woman diagnosed of systemic sclerosis. She underwent an episode of pulmonary haemorrhage, characterized by haemoptysis, sudden anaemization, and bilateral alveolar infiltration during her hospitalization, which was resolved with steroid treatment. Subsequently, she developed a focal necrotizing glomerulonephritis. After searching in the literature, we have found only three cases of systemic sclerosis associated with pulmonary haemorrhage. We discuss the etiopathogenesis of this association and stress the importance of early steroid therapy.

The Ionescu-Shiley pericardial bioprostheses in the aortic position. A 5-year perspective.

From August 1977 to August 1982, aortic valve replacement (AVR) with the Ionescu-Shiley pericardial valve was carried out on 172 patients. Hospital mortality was 4.3% for solitary AVR and 15% for patients with additional surgery. The expected 5 year survival rate was 96.7% for patients with isolated AVR and 81.8% for associated AVR. Cumulative duration of follow-up was 3,892 patient-months (mean 26.8 months per patient). The actuarial projection of freedom from thromboembolic episodes was 98.6% for isolated AVR and 91.6% for associated AVR. Seven patients underwent reoperation: 4 for infective endocarditis, 1 for massive perivalvular leak, 2 for primary tissue failure. Although the actuarial rate of freedom from valve failure for isolated AVR with Ionescu-Shiley valve was 93.7% at 5 years after surgery, the next few years of follow-up will be critical in determining the superiority of this valve over the porcine bioprostheses.

A spectroscopical measure for the exploration of phase space.

Many nonintegrable systems have eigenstates that typically require numerous basis states to represent them. We develop a criterion to judge the extent to which phase space is explored by the spectrum of such a Hamiltonian. Our criterion uses the eigenvalues rather than the eigenfunctions and is based on identifying a direct relation between the intensity of Shnirelman's peak and the localization length. We illustrate our procedure by applying it to the spectrum of two prototypical nonintegrable systems, the kicked rotor and the kicked top. (c) 1998 American Institute of Physics.

Deterministic diffusion in almost integrable systems.

Diffusion processes are usually associated with randomness in the system. In this paper we show that deterministic diffusion processes can also occur in systems with zero entropy that mimic chaos with any precision without being mathematically chaotic. A random walk model is used to predict the behavior of the diffusion coefficient. (c) 1996 American Institute of Physics.