An unusual case of hypercapnic respiratory failure.

Asphyxiating thoracic dystrophy (ATD also known as Jeune syndrome) is a very rare disorder with an incidence in the United States of 1 case per 100,000-130,000 live births. Chronic alveolar hypoventilation leading to concurrent hypoxia is the main cause of morbidity and mortality in these patients due to its complications. A 22-year-old male with past medical history of ATD and severe kyphoscoliosis presented with progressively worsening shortness of breath for several days. Past surgical history was significant for multiple reconstructive sternal surgeries, his first surgery was at the age of two. His chest exam was without wheezing and was notable for symmetrically decreased breath sounds. Arterial blood gas showed PH 7.17, PCO2 155, PO2 95 and O2 saturation of 97% on 2 L nasal cannulae. PA and lateral chest xrays showed a long and severely narrow thoracic cavity. 2D echocardiography showed left ventricular ejection fraction of 55% and evidence of severe pulmonary hypertension. CT chest angiography showed severe dilatation of the pulmonary artery in comparison to ascending aorta and significant right ventricular enlargement. Right heart catheterization confirmed these findings with a mean pulmonary arterial pressure of 61 mmHg. Within several days of hospitalization, patient developed acute worsening of his chronic hypercapnic respiratory failure thought to be due to worsening of pulmonary arterial hypertension with right heart failure. This in return was attributed to underlying ventilatory failure secondary to severe thoracic dystrophy. ATD is an autosomal recessive genetic disorder. Mutations in the IFT80 gene, which encode for an intraflagellar protein, cause this protein to be defective. Clinically, ATD is characterized by a small, narrow chest and variable limb shortness. While ATD is compatible with life, respiratory failure and infections are often fatal during infancy. Patients that survive past the age of 2 have seen respiratory complications resolve due to less pronounced thoracic malformations, but in our case the main cause of worsening pulmonary function was the degree of pulmonary arterial hypertension and right heart failure. Patients with ATD usually develop progressive hypercapnic respiratory failure due to an abnormally small thorax. Surgical options include lateral thoracic expansion or sternal and chest wall reconstruction. However, these surgeries only add a few years to survival without a definitive cure.

Subclavian artery dissection presenting as non-ST elevation myocardial infarction.

Spontaneous subclavian artery dissection is rarely reported. We report the case of a 55-year-old female who presented as an non-ST elevation myocardial infarction (NSTEMI) and was found to have a proximal left subclavian dissection. We provide an overview of current articles addressing the clinical features and treatments of subclavian dissection. To our knowledge, this is the first report of subclavian dissection presenting as an NSTEMI.

Prevalence and trends of markers of hepatitis B virus, hepatitis C virus and human Immunodeficiency virus in Argentine blood donors.

BACKGROUND: Transfusion-transmitted infections are a major problem associated with blood transfusion. The aim of this study was to determine prevalence and trends of HBV, HCV and HIV in blood donors in Argentina. METHODS: A retrospective study was carried out in blood donors of 27 transfusion centers covering the whole country over a period of eight years (2004-2011). Serologic screening assays for HBsAg, anti-HBc, anti-HCV, and anti-HIV were performed in all centers and nucleic acid amplification testing (NAT) was performed in 2 out of the 27 centers. RESULTS: The 2,595,852 samples tested nationwide from 2004 to 2011 showed that the prevalence of HBsAg decreased from 0.336% to 0.198% (p < 0.0001), that of anti-HBc from 2.391% to 2.007% (p < 0.0001), that of anti-HCV from 0.721% to 0.460%, (p < 0.0001) and that of anti-HIV from 0.208% to 0.200 (p = 0.075). The prevalence of HBV, HCV and HIV was unevenly distributed among the different regions of the country. Two out of 74,838 screening- negative samples were positive in NAT assays (1 HIV-RNA and 1 HCV-RNA); moreover, HBV-DNA, HCV-RNA and HIV-RNA were detected in 60.29, 24.54 and 66.67% of screening-positive samples of the corresponding assays. As regards donors age, positive HBV-DNA and HCV-RNA donors were significantly older than healthy donors (46.6, 50.5 and 39.5 y respectively, p < 0.001). CONCLUSIONS: Argentina has a low prevalence of HBsAg, anti-HCV and anti-HIV in blood donors, with a decreasing trend for HBsAg, anti-HBc and anti-HCV but not for anti-HIV over the last 8 years. The uneven distribution of transfusion-transmitted infections prevalence among the different regions of the country highlights the need to implement regional awareness campaigns and prevention. The discrepancy between samples testing positive for screening assays and negative for NAT assays highlights the problem of blood donors who test repeatedly reactive in screening assays but are not confirmed as positive upon further testing. The uneven distribution of age between healthy donors and NAT-positive donors could be related to changes in risks of these pathogens in the general population and might be attributed to a longer exposure to transmission risk factors in elderly people.

Percutaneous Stent-Graft Repair of Anastomotic Pseudoaneurysms following Vascular Bypass Procedures: A Report of Two Cases.

Anastomotic pseudoaneurysms are common entities following vascular bypass procedures and, if left untreated, serious complications such as thromboses, infection, and rupture can frequently occur. Therefore, attempts to employ various methods of repair have been utilized in treating anastomotic pseudoaneurysms to maximize operational success and future risk reduction. Herein, the authors report two cases of anastomotic pseudoaneurysms which were repaired percutaneously utilizing a combination of strategies such as careful preoperational image planning, multiple commercially available devices, and secondary embolization techniques.

Analysis of cocaine and benzoylecgonine in urine by using multisyringe flow injection analysis-gas chromatography-mass spectrometry system.

In this paper, a method was described to determine cocaine (COC) and benzoylecgonine (BZE) in human urine samples by GC-MS detection. The extraction of analytes from urine samples was achieved in an Oasis hydrophilic-lipophilic balance column (20 mmx3.9 mm id, dp=25 microm; Waters, USA), incorporated in a multisyringe flow injection system, used for the sample treatment. Finally, to improve the volatility of the BZE, an in-line derivatization reaction with N,O-bis (trimethylsilyl) trifluoroacetamide with 1% trimethylchlorosilane was made microwave-assisted in order to reduce the reaction time. The results showed that the proposed method is a good alternative for the analysis of COC and BZE in urine samples because it offers advantages compared with those described in the literature, which include simplicity in the sample treatment, the sensitivity and selectivity necessary to determine the analytes of interest at low levels in the urine and high sample throughput.

An environmental friendly method for the automatic determination of hypochlorite in commercial products using multisyringe flow injection analysis.

A multisyringe flow injection analysis system was used for the determination of hypochlorite in cleaning agents, by measurement of the native absorbance of hypochlorite at 292 nm. The methodology was based on the selective decomposition of hypochlorite by a cobalt oxide catalyst giving chloride and oxygen. The difference of the absorbance of the sample before and after its pass through a cobalt oxide column was selected as analytical signal. As no further reagent was required this work can be considered as a contribution to environmental friendly analytical chemistry. The entire analytical procedure, including in-line sample dilution in three steps was automated by first, dilution in a stirred miniature vessel, second by dispersion and third by in-line addition of water using multisyringe flow injection technique. The dynamic concentration range was 0.04-0.78 gL(-1) (relative standard deviation lower than 3%), where the extension of the hypochlorite decomposition was of 90+/-4%. The proposed method was successfully applied to the analysis of commercial cleaning products. The accuracy of the method was established by iodometric titration.

Sequential injection analyzer for glycerol monitoring in yeast cultivation medium.

A smart and versatile flow system for the at-line monitoring of glycerol based on sequential injection analysis is proposed. Formaldehyde, generated by oxidation of glycerol with sodium periodate, is transformed into 2,4-diacetyl-1,4-dihydrolutidine applying the Hantzsch condensation reaction with acetylacetone and ammonium. Dual-wavelength detection was carried out to minimize the contribution of the schlieren effect using a single blue LED. In-line sample dilution is accomplished applying the concept of zone-penetration and a new concept of sample splitting. Under optimized physical and chemical variables, regression curves over two dynamic working ranges of 0.1-4 and 1-40g l(-1) were attained. The injection throughputs were 14 and 12h(-1), respectively. Applying on-line data evaluation and conditional inquiries, the smart and independent selection of the adequate analytical procedure for the required working range was accomplished. The system was successfully applied to the at-line monitoring of glycerol in a continuous, cell-free medium flow from a yeast cultivation process during batch and fed-batch phase with glycerol as the only carbon source.

Development of a new high performance low pressure chromatographic system using a multisyringe burette coupled to a chromatographic monolithic column.

A novel combination of high performance low pressure chromatography with multisyringe flow injection analysis is presented. This system comprises a multisyringe module, three low pressure solenoid valves, a monolithic Chromolith Flash RP-18e column and a diode array spectrophotometer. UV detection is carried out at 250nm. AutoAnalysis software is used for instrumental control and automated data collection. The results obtained with multisyringe liquid chromatography (MSC) were compared with those obtained with a HPLC system using similar conditions. The chromatographic parameters were calculated from a mixture of anthracene and thiourea using a mobile phase containing acetonitrile-water (60:40) at a flow rate of 2mlmin(-1). The proposed MSC system has been successfully applied to the determination of amoxicillin, ampicillin and cephalexin using a mobile phase of sodium acetate buffer (pH 6.2, 0.1moll(-1))-methanol (90:10) at a flow rate of 2mlmin(-1). The low-cost, flexibility and simplicity of MSC should be highlighted.

Optical fiber reflectance sensor coupled to a multisyringe flow injection system for preconcentration and determination of 1-naphthylamine in water samples.

A novel optical fiber reflectance sensor is coupled to a multisyringe flow injection system (MSFIA) for the preconcentration and determination of 1-naphthylamine (NPA) in water samples using C18 disks (octadecyl groups). NPA, being a first-class carcinogen, is important from a toxicological point of view and, therefore, its quantification is of considerable interest. In this study, the Griess reaction is used for sensitive and selective spectrophotometric determination of NPA. The reaction involves conversion of nitrite into nitrous acid in acidic medium followed by diazotization of sulphanilic acid and formation of a diazonium salt. The diazonium salt is then combined with NPA to form 4-(sulphophenylazo)-1-naphthylamine, an azo dye. This compound is subsequently retained onto a C18 disk followed by spectrophotometric detection at 540 nm, and it is then eluted with methanol in water (80%, v/v), so that the C18 disk is regenerated for subsequent experiments. Under the established optimum conditions, a calibration graph for NPA was constructed. Good linearity was observed within a concentration range from 10 to 160 microg l(-1). The lineal regression equation is A=(0.0027+/-0.0001) [NPA]+(0.0296+/-0.0047), r=0.9991; relative standard deviation values obtained from the analysis of 10 samples of 10, 80 and 160 microg l(-1) are 4.7, 1.2 and 0.6%, respectively. The mean value relative errors for concentrations of 10, 80, 160 microg l(-1) are 3.4, 0.9 and 0.4%, respectively. The detection and quantification limits were 1.1 and 3.7 microg l(-1). A sampling throughput of 14 injections per hour is achieved. The repeatability calculated for five different C18 disks was E(rel)=2.8%. The proposed technique has been validated by replicate analysis (n=6) of several water samples with spiked NPA, giving satisfactory results.