Evaluation of substantivity of hypochlorous acid as an antiplaque agent: A randomized controlled trial.

BACKGROUND: Hypochlorous acid (HOCl) is a non-antibiotic antimicrobial substance with significant effects on pathogenic oral micro-organisms. The effects of HOCl as an antiplaque agent have not been studied. OBJECTIVE: The aim of this study was to evaluate the substantivity of HOCl mouthwashes compared with chlorhexidine (CHX) rinses and a placebo. MATERIALS AND METHODS: A double-blind randomized controlled trial with 75 participants was conducted. Participants were divided into five groups using block randomization: 0.025% HOCl, 0.05% HOCl, 0.12% CHX, 0.2% CHX, and sterile water as a placebo. Participants were instructed to use each rinse solution for 30 seconds after dental prophylaxis. Samples of saliva were taken at baseline and after 30 seconds, 1, 3, 5 and 7 hours to assess substantivity, and bacterial viability was established by the fluorescence method. Visible plaque in all participants was assessed with the Turesky index at baseline and at 7 hours, and adverse events were also assessed. RESULTS: HOCl led to a 33% reduction in bacterial counts in the saliva after 30 seconds compared with a 58% reduction by CHX. HOCl has no substantivity, and bacterial counts returned to baseline after 1 hour. Placebo treatment led to the highest plaque count after 7 hours compared with the CHX and HOCl groups, although the differences were not significant. HOCl rinsing induced the highest percentages of unpleasant taste and dryness sensations. CONCLUSIONS: HOCl rinses have an initial effect on bacterial viability in saliva but have no substantivity. Other mechanisms may explain its antiplaque effect.

Using Positive Deviance in the prevention and control of MRSA infections in a Colombian hospital: a time-series analysis.

Positive Deviance (PD) is a process to achieve a social and cultural change. This strategy has been used for the control of methicillin-resistant Staphylococcus aureus (MRSA) infection in some health institutions in the United States, but has rarely been adopted in institutions from developing countries where resources are limited. We describe our experience of PD in the control of healthcare-associated infections (HAIs) due to MRSA in a Colombian hospital with the aim of reducing HAI rates through a cultural change in processes. A time-series study was conducted based on the MRSA-HAI rate and the number of months with zero MRSA infections before and after application of PD (2001-2012). On comparing the pre-intervention and intervention periods, the mean overall rates of MRSA-HAI was 0·62 and 0·36, respectively (P = 0·0005); the number of months with zero MRSA-HAIs were 3/70 and 12/74 (odds ratio 0·264, 95% confidence interval 0·078-0·897); the percentage of MRSA-HAIs was 53·2% and 41·0%. These results are consistent with other published data. Implementation of PD was associated with a significant reduction of MRSA-HAIs, it did not involve high costs and the changes have been lasting.

Cerebrospinal fluid and plasma oxytocin concentrations are positively correlated and negatively predict anxiety in children.

The neuropeptide oxytocin (OXT) exerts anxiolytic and prosocial effects in the central nervous system of rodents. A number of recent studies have attempted to translate these findings by investigating the relationships between peripheral (e.g., blood, urinary and salivary) OXT concentrations and behavioral functioning in humans. Although peripheral samples are easy to obtain in humans, whether peripheral OXT measures are functionally related to central OXT activity remains unclear. To investigate a possible relationship, we quantified OXT concentrations in concomitantly collected cerebrospinal fluid (CSF) and blood samples from child and adult patients undergoing clinically indicated lumbar punctures or other CSF-related procedures. Anxiety scores were obtained in a subset of child participants whose parents completed psychometric assessments. Findings from this study indicate that plasma OXT concentrations significantly and positively predict CSF OXT concentrations (r=0.56, P=0.0064, N=27). Moreover, both plasma (r=-0.92, P=0.0262, N=10) and CSF (r=-0.91, P=0.0335, N=10) OXT concentrations significantly and negatively predicted trait anxiety scores, consistent with the preclinical literature. Importantly, plasma OXT concentrations significantly and positively (r=0.96, P=0.0115, N=10) predicted CSF OXT concentrations in the subset of child participants who provided behavioral data. This study provides the first empirical support for the use of blood measures of OXT as a surrogate for central OXT activity, validated in the context of behavioral functioning. These preliminary findings also suggest that impaired OXT signaling may be a biomarker of anxiety in humans, and a potential target for therapeutic development in individuals with anxiety disorders.

Design of organic scintillators for non-standard radiation field dosimetry: experimental setup.

This paper describes an experimental setup designed for sensing the luminescent light coming from an organic plastic scintillator stimulated with ionizing radiation. This device is intended to be a part of a complete dosimeter system for characterization of small radiation fields which is the project of the doctoral thesis of the medical physicist at the Radiation Oncology facility of Hospital San Vicente Fundación in conjunction with the Universidad de Antioquia of Medellín Colombia. Some preliminary results predict a good performance of the unit, but further studies must be conducted in order to have a completed evaluation of the system. This is the first step in the development of an accuracy tool for measurement of non-standard fields in the Radiotherapy or Radiosurgery processes.

Antiarrhythmic agents: drug interactions of clinical significance.

The management of cardiac arrhythmias has grown more complex in recent years. Despite the recent focus on nonpharmacological therapy, most clinical arrhythmias are treated with existing antiarrhythmics. Because of the narrow therapeutic index of antiarrhythmic agents, potential drug interactions with other medications are of major clinical importance. As most antiarrhythmics are metabolised via the cytochrome P450 enzyme system, pharmacokinetic interactions constitute the majority of clinically significant interactions seen with these agents. Antiarrhythmics may be substrates, inducers or inhibitors of cytochrome P450 enzymes, and many of these metabolic interactions have been characterised. However, many potential interactions have not, and knowledge of how antiarrhythmic agents are metabolised by the cytochrome P450 enzyme system may allow clinicians to predict potential interactions. Drug interactions with Vaughn-Williams Class II (beta-blockers) and Class IV (calcium antagonists) agents have previously been reviewed and are not discussed here. Class I agents, which primarily block fast sodium channels and slow conduction velocity, include quinidine, procainamide, disopyramide, lidocaine (lignocaine), mexiletine, flecainide and propafenone. All of these agents except procainamide are metabolised via the cytochrome P450 system and are involved in a number of drug-drug interactions, including over 20 different interactions with quinidine. Quinidine has been observed to inhibit the metabolism of digoxin, tricyclic antidepressants and codeine. Furthermore, cimetidine, azole antifungals and calcium antagonists can significantly inhibit the metabolism of quinidine. Procainamide is excreted via active tubular secretion, which may be inhibited by cimetidine and trimethoprim. Other Class I agents may affect the disposition of warfarin, theophylline and tricyclic antidepressants. Many of these interactions can significantly affect efficacy and/or toxicity. Of the Class III antiarrhythmics, amiodarone is involved in a significant number of interactions since it is a potent inhibitor of several cytochrome P450 enzymes. It can significantly impair the metabolism of digoxin, theophylline and warfarin. Dosages of digoxin and warfarin should empirically be decreased by one-half when amiodarone therapy is added. In addition to pharmacokinetic interactions, many reports describe the use of antiarrhythmic drug combinations for the treatment of arrhythmias. By combining antiarrhythmic drugs and utilising additive electrophysiological/pharmacodynamic effects, antiarrhythmic efficacy may be improved and toxicity reduced. As medication regimens grow more complex with the aging population, knowledge of existing and potential drug-drug interactions becomes vital for clinicians to optimise drug therapy for every patient.

Vancomycin assay performance in patients with acute renal failure.

OBJECTIVE: Fluorescence polarization immunoassays (FPIA) have been reported to overestimate vancomycin serum concentrations compared to high-performance liquid chromatography (HPLC) or enzyme multiplied immunoassay technique (EMIT) in patients with chronic renal disease. The assay manufacturer has modified the FPIA to remedy this overestimation. The purpose of this study was to compare the assay performance of two FPIAs to EMIT in acute renal failure patients receiving vancomycin and continuous venovenous hemofiltration. DESIGN: Open-label trial. SETTING: Intensive care unit in a university affiliated hospital. PATIENTS AND PARTICIPANTS: 15 serum and ultrafiltrate samples were obtained from 14 critically ill patients (mean +/- SD; 57 +/- 12 years; 8 males/6 females). MEASUREMENTS AND RESULTS: Vancomycin concentrations were determined by a polyclonal FPIA (pFPIA) performed on the TDx system, a monoclonal FPIA (mFPIA) performed on the AxSYM system and EMIT. The coefficient of variation for all assays was < 5%. The mean difference +/- SDd between mFPIA vs EMIT and pFPIA vs EMIT assays in serum were: -0.08 +/- 1.55 and 1.24 +/- 2.11 mg/l, respectively. The limits of agreement between the mFPIA vs EMIT and pFPIA vs EMIT assays in serum were: -3.18 to 3.03 and -2.99 to 5.46 mg/l, respectively. CONCLUSIONS: Our data demonstrate that the manufacturer's changes to the pFPIA have reduced overestimation. The mFPIA appears to be an acceptable assay for measuring vancomycin serum concentrations in acute renal failure patients and does not significantly overestimate these concentrations.

[GASTRODUODENAL ULCER IN PEDIATRICS] / Ulcera gastroduodenal en Pediatría.

476 endoscopic reports of 435 children under 15 years old of both sexes were reviewed to determine the morbility of gastroduodenal peptic ulcer. Endoscopy was performed because they had symptoms referred to the upper gastrointestinal tract between December 1989 and December 1994. Gastroduodenal ulcer was diagnosed in forty five children (10,3%). Primary ulcer was diagnosed in twenty four patients (55%) and secondary ulcers in twenty one (45%), being the administration of ulcerogenic drugs the main factor involved. Primary ulcer was more frequently diagnosed in older children and teenagers and localized mainly in the duodenum. Male sex was predominant in both types of ulcers. 42% of children with primary ulcers had familiar ocurrence of ulcer disease. Thirty three patients (73%) had complications, being gastrointestinal bleeding the most frequent. Ulcer disease is not rare in children and must be suspected in patients with recurrent abdominal pain.

[PREVALENCE OF ANTI-HCV IN HOSPITALIZED CHILDREN] / Prevalencia del anticuerpo contra el virus de laHepatitis C en niños hospitalizados.

In the last years, one of the causative agents of post-transfusion non A non B hepatitis has been identified as hepatitis virus C(HCV). In order to determine the HCV prevalence in a pediatric population, an anti-HCV determination through Cuban manufactured Microelisa system was done to 500 hospitalized children under 14 years old, of both sex, for six months. The samples repeatedly reactive were considered positive, the risk factors for this infection were evaluated and the Relative Risk was estimated. Seven patients (1,4% of the sample) were HCV-positive, and underwent clinical, biochemical, immunological, echographic, laparoscopic and histological examinations to determine the hepatic damages associated to the presence of this virus. The Relative Risk for HCV is 4,5 times more for those with previous surgical operation, 3,9 for those who have had more than four previous hospitalizations and, of 2,6 and 1,9 for those with previous transfusion and treatment with vaccine, respectively. The predominant histological lesion reported was a minimum damage of the liver cells. It is important to screen for HCV in blood banks and to study other possible routes of transmission. We recommend the follow up of these patients for the possibility of cronical sequela.

Cáncer de colon: eficacia de la radiografía a doble contraste / Colon cancer: double contrast radiography efficacy

El objetivo del presente estudio fué determinar la frecuencia en la cual una radiografía de colon a una doble contraste permite un diagnóstico correcto en el carcinoma de colon. El estudio fué hecho en el Hospital Edgardo Rebagliati Martins del IPSS en Lima. Previamente fué identificada la prevalencia el carcinoma de colon en el lugar del estudio entre 1980 y 1991, este fué 5 por ciento. Nosotros elegimos un número representativo de pacientes, 50 con un diagnóstico confirmado histopatologicamente de carcinoma de colon, en el cual una radiografía de colon a doble contraste (DC) fué hecha antes de que se hiciera el diagnóstico. El grupo control, incluyó 50 pacientes con otra patología colónica, distinta al carcinoma, en el cual una DC fué realizada previamente al diagnóstico. La sensibilidad y especificidad fueron 84 ñ 10 por ciento y 94 ñ 6 por ciento respectivamente para DC. El valor predictivo positivo fue 93 ñ 7 por ciento, y el valor predictivo negativo fué 85 ñ 10 por ciento y la eficacia 89+9 por ciento. Concluimos que la radiografía de colon a doble contraste es de gran utilidad para el diagnóstico de carcinoma de colon

Diagnostic ability of different human milk fat globule antigens in breast cancer.

Human mammary epithelial antigens (HME-Ags) are released into the circulation by breast tumors and not by normal breast tissue (Proc. Natl. Acad. Sci. USA 74: 582-586, 1977). This characteristic made them valuable, together with other breast cancer related antigens later identified, to develop immunoassays useful in the follow-up of breast cancer. Assays for these antigens in serum have less than complete sensitivity and partial specificity, and as a result of this have not been totally successful in studying the relapsing breast cancer patient. In the present work, correlations are made among 3 assays available for breast cancer disease follow-up. They detect HME-Ags, CEA, and the heavy molecular weight mucin of the human milk fat globule (HMFG). Values for sensitivity and specificity for the 3 assays were obtained from approximately 300 samples of patients whose clinical diagnosis at the time of blood drawing was rigorously established. A small but definite advantage in sensitivity is demonstrated for the HME-Ags assay over the other two. A similar advantage is also demonstrated in the sequential follow-up of breast cancer patients, where HME-Ags respond more rapidly in most instances to changes in tumor burden. Further, the ability of increases in levels of these assays to predict relapse was studied in 15 patients who relapsed. HME-Ags demonstrated a predictive value of 73%, while CEA and the heavy molecular weight mucin remained at 47%. The present study exemplifies the search for novel antigens (Ags) with maximal ability to detect breast cancer relapse and with improved sensitivity to monitor tumor burden changes. Here, assays for different antigens to be compared are tested in the same serum samples obtained from carefully staged patients. The results suggest a role as breast cancer markers for antigens of lower molecular weight than the epithelial mucin-like components studied previously.

Biological effects of the Los Alamos meson beam on cells in culture.

Preliminary measurements of the biological effects of negative pions on cells in culture are reported. Cell survival as a function of depth was obtained by using gelatin to suspend the cells. The results indicate that the effects are more pronounced at the peak portion of negative pions. Cell-survival curves were also obtained under oxygenated and hypoxic conditions. The biological effectiveness at the peak was found to be a factor of 2.0 higher than at the plateau. The oxygen enhancement ratio was 1.5 at the peak. No significant differences in biological effects were observed above 14 mm in the peak region.

Cell classification by laser light scattering: identification and separation of unstained leukocytes.

We have used a flow-system cell sorter to separate unfixed, unstained human leukocyte cells into morphologically distinct populations based only on the intensity of 488-nm wavelength laser light simultaneously scattered by each cell at two different angles. Three populations were observed as distinct peaks in a two-parameter pulse-height distribution and were then physically sorted into separate classes and stained for cytological examination. The three groups consisted of lymphocytes, monocytes, and neutrophils. Each group contained between 77 and 98 per cent of a single cell type. Blood from an irradiated monkey was also sorted and showed the presence of a fourth peak which consisted of 61 per cent eosinophils. Thus, multiangle light-scattering information from unfixed, unstained cells may be a promising technique for rapid morphologic analysis and may have application, for example, as a highspeed automated leukocyte differential. We anticipate that this method may be useful in other clinical applications where morphologic differences are diagnostically important. One of the principal advantages of the method is elimination of fixation and staining of the samples; this is a nondestructive testing technique.

The effect of methionine, thiouracil, dienestrol diacetate and thyroprotein on the development and prevention of fatty liver in pullets.

The effect of two levels each of methionine (0.0 and 0.07 percent), thiouracil (0.0 and 0.05 percent), dienestrol diacetate (0.0 and 0.007 percent), and thyroactive casein (0.0 and 0.0125 percent) on the performancy, organ changes, and liver composition in 640 pullets of two strains was studied in a 24 factorial arrangement of treatments. Egg production, egg characteristics, feed conversion, organ weights, and liver composition were parameters measured. Supplemental methionine increased the phosphorus content of liver fat in strain A, but other parameters in the two strains were mot affected by the increase in dietary methionine. The thiouracil increased weight grains, gram of fat per total liver, percent of liver fat, thyroid weight, and heart weight but decreased the phosphorus content of liver fat. Nine typical cases of fatty liver syndrome with large liver hematomas occurred in the thiouracil treated birds and one case occurred in an untreated pullet. Dienestrol diacetate did not affect egg production, egg characteristics, organ weights, and liver composition in the two strains. Thyroprotein decreased weight gain, abdominal fat, liver weight. liver fat, thyroid weight, and percent red cells, but decreased percent blood sports in eggs and adjusted weights of the kidney and heart in both strains.