[Incidence of phlebitis due to peripherally inserted venous catheters: impact of a catheter management protocol]. / Incidencia de flebitis secundaria por catéter venoso de acceso periférico e impacto de un protocolo de manejo.

OBJECTIVE: To assess the impact on the incidence of PPIVC by implementing a catheter management protocol and to determine risk factors for PPIVC development in hospitalized patients. METHOD: A total of 3978 episodes of venous catheterization were prospectively included from September 2002 to December 2007. A catheter management protocol was implemented during this period of time. The incidence and variables associated to the occurrence of PPIVC were determined. RESULTS: The incidence of PPIVC from 2002 to 2007 was 4.8%, 4.3%, 3.6%, 2.5%, 1.3% and 1.8% (p<0.001). Perfusion of amiodarone [adjusted OR (AOR) 25.97; 95% CI=7.29-92.55, p=0.0001] and cefotaxime (AOR 2.90; 95% CI=1.29-6.52, p=0.01) and the shift when the catheters were placed (AOR for morning vs. night shift 0.60; 95% CI=0.35-1.02, p=0.063) were independently associated to the development of PPIVC. A history of phlebitis was the only factor independently associated to phlebitis due to peripherally inserted central venous catheters (AOR 3.24; CI at 95% CI= 1.05-9.98, p=0.04). CONCLUSIONS: A catheter management protocol decreases the incidence of PPIVC in hospitalized patients. The risk of PPIVC increases for peripherally inserted central venous catheters when the patients have a history of phlebitis and for peripheral venous catheters when amiodarone or cefotaxime are infused. Catheterization of peripheral veins performed during morning shifts is associated with a lower incidence of PPIVC when compared with night shift catheterizations.

[Dissociated cholestasis in patients with HIV-1 infection, Prevalence and diagnostic value of liver biopsy]. / Colestasis disociada en pacientes infectados por el VIH-1. Prevalencia y valor diagnóstico de la biopsia hepática.

HIV-1 infected patients frequently develop opportunistic diseases involving the liver, particularly individuals with AIDS. Nevertheless, the role of liver biopsy (LB) in these patients is controversial. The prevalence of AC in seropositive subjects and the value of LB in patients with AC was investigated. The prevalence of AC in all outpatients attended at our Unit for a three month period was 2/119 (1.6%), whereas it was 20/66 (30.3%) for inpatients for a nine month period. LB was proposed to all patients with AC but not to those with a Karnofski index < 50 and those with an ethanol intake > 80 g per day. LB was performed in 16 patients, four were excluded, and 2 refused the procedure. Among symptomatic patients, LB: a) confirmed a previous diagnosis in six patients (40%); b) showed findings of nonspecific cholangitis in four cases (27%), and c) disclosed a previously unsuspected or unconfirmed disease in five patients (33%). LB is an useful diagnostic tool for the diagnosis of seropositive patients with AC, although a previous opportunistic event may account for symptoms and the corresponding enzymatic patterns.

An outbreak of hantavirus pulmonary syndrome, Chile, 1997.

An outbreak of 25 cases of Andes virus-associated hantavirus pulmonary syndrome (HPS) was recognized in southern Chile from July 1997 through January 1998. In addition to the HPS patients, three persons with mild hantaviral disease and one person with asymptomatic acute infection were identified. Epidemiologic studies suggested person-to-person transmission in two of three family clusters. Ecologic studies showed very high densities of several species of sigmodontine rodents in the area.

Vascular response to guided tissue regeneration procedures using nonresorbable and bioabsorbable membranes in dogs.

Revascularization of the periodontal tissues was studied following guided tissue regeneration (GTR) procedures using both nonresorbable and bioabsorbable membranes. The procedures were performed in 8 female beagle dogs, 4 to 6 years old. Second, third, and fourth mandibular premolars were involved; experimental periods covered from 3 days to 49 days. After elevation of soft tissue flaps, Class II furcation defects were prepared by removing buccal alveolar bone from the teeth and exposed root surfaces were planed in order to remove root cementum. The quadrant was then flushed with sterile saline. Randomly selected, in one quadrant, the second and fourth premolars received nonresorbable expanded polytetrafluoroethylene (ePTFE) membranes. The other quadrant, second and fourth premolars, received the bioabsorbable membranes, made of glycolide and lactide polymers. After the membranes were in place, they were sutured. The third premolars of both quadrants served as negative controls. The animals were sacrificed by exsanguination under general anesthesia and then perfused through the carotid arteries with a combined solution of equal parts of India ink and 10% buffered formalin. Following fixation and demineralization, part of the blocks were processed to obtain cleared specimens following the method of Spalteholtz. The remaining blocks were processed for routine histologic examination. The findings, mainly from the cleared specimens, showed that at the early phase of healing, ePTFE membranes interfered with the revascularization while they were in place. Contrary to this, bioabsorbable membranes allowed earlier anastomosis of the vasculature of the flap and regenerated tissues. However, the long-term vascular response was similar for both membranes.

Giardia muris trophozoite antigenic targets for mouse intestinal IgA antibody.

The aim of this work was to characterize Giardia muris trophozoite proteins that are targets for intestinal anti-trophozoite IgA in G. muris-infected mice. Intestinal secretions were obtained from immunocompetent BALB/c mice that had been infected with G. muris cysts 4-5 weeks previously and from control uninfected BALB/c mice. Flow cytometry of G. muris trophozoites that had been incubated with intestinal secretions and with fluorescein isothiocyanate-conjugated anti-mouse IgA showed that anti-trophozoite IgA was present in intestinal secretions obtained from infected BALB/c mice. By immunoblotting on G. muris trophozoite proteins separated by one-dimensional gel electrophoresis, this IgA recognized at least one trophozoite protein of molecular mass of approximately 80 kDa. The 80-kDa G. muris protein(s) has a molecular mass similar to that described for cysteine-rich surface proteins of the human parasite Giardia lamblia.

Changes in lung morphology and cell number in radiation pneumonitis and fibrosis: a quantitative ultrastructural study.

We used stereologic-morphometric techniques to obtain a detailed quantitative picture of the changes in lung ultrastructure of rats at 12 and 26 weeks after unilateral thoracic irradiation with 3000 cGy. At 12 weeks post-radiation, the total number type 1 epithelial cells, type 2 epithelial cells and capillary endothelial cells were decreased 50-70%, total type 1 epithelial and capillary surface areas were decreased 55-60%, and the total volume of intracapillary blood was decreased 75%. The interstitial cells and matrix together accounted for more than 9% of the peripheral lung tissue volume including air, compared to 3% in controls. The numerical density of interstitial cells was increased to 3-fold the control value. The numerical density of interstitial cells was increased to 3-fold the control value. Although fibroblasts still comprised the largest interstitial cell subgroup, the numerical density of mast cells was increased over 150-fold and other inflammatory and immune cells were increased to a lesser extent. At 26 weeks post-radiation, the number, volume, and surface area of the type 1 epithelium and capillary endothelium had further decreased to only 5-10% of control values. The total number of type 2 epithelial cells was reduced by 75% but the volume density was actually increased because of a 4-fold increase in the mean cell volume. The interstitial cells and matrix now comprised over 77% of total peripheral lung tissue volume including air as compared to 6% in controls. Mast cells and plasma cells comprised 11% and 19% of all interstitial cells respectively and the densities of these cells were 540 and 180-fold the control value respectively. The relation of these morphometric findings to the results of previous morphologic studies is discussed.

Improved negative staining of microfilament arrangements in detergent-extracted Physarum amoeboflagellates.

A motile, lamellipodium-like structure, the ridge, forms as amoeboflagellate cells of Physarum polycephalum release from a substratum and begin swimming in fluid. Actin microfilaments form a distinct laminar core within the ridge; they are seen as a sparse, disordered meshwork in cytoskeletons prepared by conventional methods using uranyl acetate negative staining [10]. Preservation and visualization of these filaments and their arrangements improved considerably when cytoskeletons were imaged with phosphotungstic acid buffered with ammonium hydroxide (PTA(NH4]. Microfilaments within ridge cytoskeletons were found to form loose bundles and criss-crossing, 'meshwork' arrays several layers deep. Differences could be detected in morphology and detailed arrangement of microfilaments within cytoskeletons prepared in the presence of phalloidin. PTA(NH4) may be useful for studies of cytoskeletal elements and their rearrangements in dynamic, motile regions of cells.

A spin label study of the urinary bladder luminal membrane.

Spin label experiments have been carried out on the urinary bladder luminal membrane of the bovine transitional epithelium employing the 5-, 7-, 12-, and 16-doxyl substituted stearic acid methyl esters, and compared for reference to similarly labeled bovine erythrocytes. The bladder membranes are significantly different from the bovine red blood cell membranes and show a lower order and polarity near the membrane surface. This fact and the general similarity of results for the bladder and isolated plaque membranes suggests that the highly organized proteins of the bladder membrane may act as a coat on the lipid bilayer and, while intrinsic in nature, do not significantly perturb the hydrophobic core of the lipid bilayer.

Morphology of the intermediate stages in the lamellar to hexagonal lipid phase transition.

The addition of calcium to suspensions of egg phosphatidylcholine and cardiolipin converts multiwalled liposomes to the hexagonal (HII) phase (Rand, R.P., Sengupta, S. (1972) Biochim. Biophys. Acta 255:484-492). We have studied this lamellar to hexagonal phase transition by freeze-fracture, thin-section electron microscopy, and X-ray diffraction and have morphologically characterized the intermediate stages. The first step in the transition involves the invagination and fusion of bilayers, marked by the appearance of lipidic intramembrane particles and "crater-like" indentations, as the large liposomes are converted to smaller flattened and elongated vesicles. The next step is the formation of tightly packed hexagonal arrays of tubules, each tubule being about 11 to 15 nm in diameter. These tubules are filled with fluid and a lipid bilayer forms the wall of each cylinder. Finally this tubular bilayer phase is converted to the hexagonal (HII) phase, where the distance between tubes is 5.5 to 7.5 nm.