Contrast-enhanced ultrasonography to guide diagnostic and therapeutic interventional procedures.

Although not necessary for the vast majority of ultrasound-guided procedures, intravenous contrast agents can be useful for procedures aimed at lesions that require contrast enhancement to be seen on ultrasonography. Using contrast-enhanced ultrasonography to guide procedures has two drawbacks: first, because enhancement from ultrasound contrast agents is short lived, it is often necessary to plan several injections; second, because the needle is poorly seen on contrast-enhanced ultrasonography, a dual image display format is necessary. Contrast-enhanced ultrasonography can be used for planning and monitoring diagnostic and therapeutic procedures, for guiding the procedures, and for follow-up. Using contrast-enhanced ultrasonography enables better results in both types of procedures; moreover, it can be used within cavities.

Contrast-enhanced ultrasonography to guide diagnostic and therapeutic interventional procedures. / Ecografía con contraste en procedimientos ecoguiados.

Although not necessary for the vast majority of ultrasound-guided procedures, intravenous contrast agents can be useful for procedures aimed at lesions that require contrast enhancement to be seen on ultrasonography. Using contrast-enhanced ultrasonography to guide procedures has two drawbacks: first, because enhancement from ultrasound contrast agents is short lived, it is often necessary to plan several injections; second, because the needle is poorly seen on contrast-enhanced ultrasonography, a dual image display format is necessary. Contrast-enhanced ultrasonography can be used for planning and monitoring diagnostic and therapeutic procedures, for guiding the procedures, and for follow-up. Using contrast-enhanced ultrasonography enables better results in both types of procedures; moreover, it can be used within cavities.

[Ultrasound-guided interventional procedures in the musculoskeletal system]. / Intervencionismo guiado por ecografía en el sistema musculoesquelético.

Ultrasonography is the most appropriate tool for interventional procedures in the musculoskeletal system when the lesion is visible on ultrasonography. Procedures performed under ultrasonographic guidance include: taking biopsies; draining abscesses; bursitis; hematomas or muscle tears; treating cystic lesions; diagnostic or therapeutic arthrocentesis; injecting substances into joints or lesions; aspirating calcium deposits and extracting foreign bodies. Although some of these procedures are often carried out without imaging guidance, ultrasonographic guidance improves their efficacy. Drainage can be performed with catheters or needles and makes it possible to avoid more aggressive treatments in most cases. Urokinase is useful for draining hematomas or fibrinous collections. Injecting corticoids is useful in the treatment of synovial cysts, Baker's cyst, tendinitis, and non-infective arthritis. Calcifying tendinitis of the shoulder can be treated effectively with percutaneous calcium lavage.

[US-guided interventional procedures: what a radiologist needs to know]. / Intervencionismo guiado por ecografía: lo que todo radiólogo debe conocer.

US has important advantages in guiding interventional procedures: it is economical and widely available, it does not use ionizing radiation, and it requires less time than other techniques. US guidance can be provided using devices adapted to probes or using the freehand technique (holding the needle in one hand and the probe in the other). US-guided procedures require careful planning, adequate hemostasis or a directly compressible puncture site, the patient's informed consent, and appropriate measures to ensure asepsis and anesthesia. The technique involves introducing the needle or catheter through the plane of the US slice. The advance of the needle is controlled in real time. High resolution linear probes are ideal for interventional procedures in superficial tissues, but 3.5 MHz probes are required for procedures in deep tissues. The most common procedures include biopsies, drainages, and percutaneous injections. Biopsies can be carried out using fine needles to obtain material for cytological study (fine-needle aspiration cytology) or using large needles to obtain specimens for histologic study (core biopsy). Core biopsy is more sensitive and more specific, and it has a low rate of complications. Drainage almost always involves placing a catheter in a fluid collection; it can be done using the Seldinger techniques, trocars, or pleural catheters. US-guided percutaneous injections can be used to inject substances into infectious lesions, tumors, or nerve plexuses, and they are especially useful in musculoskeletal disease.

Automated determination of apolipoproteins A-I and B with an improved immunoturbidimetric assay using Boehringer Mannheim and Hitachi analyzer systems.

Results from an evaluation of immunoturbidimetric methods (Tina-quant) for apolipoprotein A-I (apo AI) and apolipoprotein B (apo B), are presented and compared with results from six other commercial immunoassays. These apo AI and B procedures are fully automated on the Boehringer Mannheim (BM) and Hitachi 704 and 717 analyzers and use undiluted serum. The methods provide an analytical range from 0.002 to 2.3 g/L for apo AI and from 0.003 to 2.2 g/L for apo B and are precise with maximal CVs of 4%. Neither hemoglobin nor intralipid interfered with the assays. Bilirubin concentrations higher than 376 mumol/L for apo AI and 444 mumol/L for apo B, produce a negative interference. In the apo AI method a positive interference caused by rheumatoid factor was found for concentrations higher than 440 x 10(3) IU/L. All comparisons showed an excellent correlation (r > 0.93) with all methods, and slopes ranged from 1.01 to 1.25 for apo AI, and from 0.62 to 1.15 for apo B.

Case report 807: Infantile desmoid-type fibromatosis.

A case of infantile desmoid-type fibromatosis has been described and discussed. The clinical and pathological features were described, and the interrelationship of this entity with others, together with the wide range of benign structures, was discussed. Other cases resembling this one have been described.

IgG interference in second generation enzymeimmunoassays for anti-hepatitis C virus antibodies.

The interference of endogenous IgG in the identification of anti-HCV antibodies was studied in three second-generation enzymeimmunoassays. The addition of increasing concentrations of this immunoglobulin led to the appearance of false positives. The results obtained confirm the hypothesis that a non-specific binding of the IgG with the support material used was responsible for this interference.

[Lymphocyte subpopulations, neopterin, and beta-2-microglobulin: relationship with clinical stage, risk of progression to AIDS and presence of active infection in HIV infection]. / Subpoblaciones linfocitarias, neopterina y beta-2-microglobulina: relación con estadio clínico, riesgo de progresión a sida y presencia de infección activa en la infección por VIH.

BACKGROUND: The aim of the present study was to evaluate the relation between the number of CD4 lymphocytes, the CD4/CD8 ratio and the plasma levels of neopterin and beta-2 microglobulin, and the clinical status, risk of progression without of active opportunistic infections, among HIV-infected patients. METHODS: Seventy-two patients infected by HIV in different clinical groups were evaluated upon entering the study and following a mean follow up of 6 months for the parameters studied. RESULTS: The values of CD4 lymphocytes and neopterin were related with the clinical status according to the CDC's classification, with no significant differences existing in the beta-2 microglobulin level. The CD4 count as well as the neopterin and the beta-2 microglobulin levels differed significantly when classified to the patients with regard to the risk of progression to AIDS throughout the study. The presence of active opportunistic infections was related with significantly higher concentrations of neopterin without differences recorded for the remaining parameters. CONCLUSIONS: The parameters studied are good markers or both clinical status and/or the risk of short-term progression to AIDS. Neopterin levels are high during acute infections. Therefore, its prognostic value should be cautiously evaluated in this situation.

Automated latex nephelometric immunoassay for the measurement of serum lipoprotein (a).

A sensitive immunoassay based on latex particle agglutination has been developed for measuring lipoprotein Lp(a) concentrations in serum or plasma. Carboxylated latex particles (diameter 240 nm) covalently coated with F(ab')2 fragments of anti-lipoprotein Lp(a) antibodies are incubated with diluted sample (400-fold) for 12 min at room temperature, with the resulting agglutination quantified by measuring the change of light-scatter produced. The assay has been automated on the Behring nephelometer analyzer with a sampling rate of 150 samples/hour. This assay generates a standard curve in the range of 27 to 1750 mg/L, showing inter-assay precision of less than 8%. There were no interferences from plasminogen, bilirubin, Intralipid, haemoglobin, rheumatoid factor, and apolipoprotein B. No significant differences were observed when fresh and frozen samples were compared. Sample pretreatment with "Lipoclean" clearing agent and sample lyophilization decreased the agglutinating reaction. In two separate studies using 77 and 112 patient sera the Lp(a) values, determined by the latex nephelometric method, the Terumo Macra Lp(a) ELISA test, and the Pharmacia Apo(a) radioimmunoassay method, gave correlation coefficients of 0.948 and 0.974, respectively. Physiological lipoprotein (a) values were determined in a blood donor group, with the distribution of serum Lp(a) highly skewed, with a mean (SD) and median values of 213(236) mg/L and 116 mg/L, respectively. Concentrations of Lp(a) were found to be age- and sex-independent. This latex nephelometric procedure is a convenient method and an interesting alternative to other immunoassays for routine measurement of human lipoprotein (a).

Automated latex nephelometric immunoassay of theophylline in human serum.

A latex test was adapted for the nephelometric quantitation of theophylline in human serum. The assay is fully automated on the Behring Nephelometer Analyser with a sampling rate of 150 samples per hour. There is no interference from bilirubin (up to 340 mumol/l), haemoglobin (up to 7000 mg/l), Intralipid (up to 5 g/l), or rheumatoid factor (up to 1100 x 10(3) IU/l). The theophylline standard curve extends from 1.25 to 40 mg/l. The coefficient of variation ranged from 2.4 to 7.4%. The correlation coefficient between the latex immunoassay and the TDx theophylline procedure was 0.988, calculated from the assay of 74 samples.

Automated quantitative nephelometric latex immunoassay for determining ferritin in human serum.

We describe a rapid and sensitive latex nephelometric immunoassay for quantifying ferritin in human serum. This latex immunoassay procedure uses commercially available ready-for-use reagents [Tina-Quant (a) Ferritin, Boehringer Mannheim] that have a long shelf life. The assay consists of incubating the diluted serum sample (5-fold) for 12 min at room temperature with latex particles covalently coated with anti-ferritin antibodies, and then quantifying the change of light-scatter produced. The assay is fully automated on the Behring nephelometer analyzer with a sampling rate of 150 samples/hour. The method has an analytical range of 3 to 260 micrograms/l. Maximal intra- and inter-assay CVs were 4.0 and 6.2%, respectively. Analytical recoveries ranged from 91.3 to 103.6%. Assay detection limit was less than 3 micrograms/l. Linearity of the test is given throughout the measuring range. There was no interference from bilirubin (up to 340 mumol/l), haemoglobin (up to 7 g/l), or rheumatoid factor (up to 1,100 IU/ml). Turbid and lipemic samples interfere. This interference may be avoided by pretreating these samples prior to assay. Results correlated well with those obtained by an automated ELISA test (r = 0.995) and with those of two commercial RIA methods (r greater than 0.97). This latex nephelometric procedure is a convenient method and represents an interesting alternative to other immunoassays for measuring ferritin in human serum.

Rheumatoid arthritis and hepatitis C virus antibodies.

The prevalence of antibodies against the hepatitis C virus (anti-HCV) in patients seropositive for rheumatoid arthritis (RA) and suffering from this disease has been analyzed in comparison to a control group. Our results suggest that the high rate of prevalence found in RA patients is due to IgG interference in the measuring method used.