Biomonitoring using accessible human cells for exposure and health risk assessment

We describe a nonradioactive preembedding in situ hybridization protocol using digoxigenin-labeled RNA probes and tyramide signal amplification to increase the sensitivity of detection. The protocol is sensitive enough for electron microscopic localization of endogenous messenger RNAs encoding beta-actin and amphoterin. Three visualization methods were compared: diaminobenzidine enhanced by nickel, Nanogold enhanced by silver and gold toning, and fluorescently labeled tyramides. Diaminobenzidine and Nanogold can be used in both light and electron microscopy. The nickel-enhanced diaminobenzidine was the most sensitive visualization method. It is easy to accomplish but a drawback is poor spatial resolution, which restricts its use at high magnifications. Nanogold visualization has considerably better spatial resolution and is therefore recommended for electron microscopy. Fluorescent tyramides, especially TRITC-tyramide, offer a good detection method for fluorescence and confocal microscopy. The methods were used to localize amphoterin and beta-actin mRNAs in motile cells. Both mRNAs were found in the soma and cell processes. In double labeling experiments, beta-actin mRNA localized to filamentous structures that also contained ribosomal proteins. Especially in the cortical cytoplasm, beta-actin mRNA was associated with actin filaments. Direct localization to microtubules was only rarely seen. (J Histochem Cytochem 47:99-112, 1999)     

Segmental antigen challenge increases fibronectin in bronchoalveolar lavage fluid

Fibronectin may contribute to asthma pathogenesis by recruitment and activation of inflammatory cells, and by promotion of subepithelial fibrosis. Fibronectin is produced by several types of airway cells, including epithelial cells, fibroblasts, and alveolar macrophages. To test the hypothesis that antigen-induced airway inflammation is associated with increased local generation of fibronectin, segmental bronchoprovocation (SBP) with antigen and saline was performed in 17 atopic patients. Bronchoalveolar lavage (BAL) was performed at 5 min and 48 h after segmental challenge with saline or antigen. Fibronectin concentrations in BAL fluid, measured by enzyme-linked immunosorbent assay (ELISA), increased more than 5-fold 48 h after antigen challenge (65 [47 to 110] versus 407 [240 to 697] ng/ml, median and 25 to 75% interquartiles, p < 0.05). Fibronectin concentrations 48 h after antigen challenge correlated with histamine concentrations 5 min after antigen challenge and numbers of eosinophils, neutrophils, macrophages, and total cells in BAL fluid 48 h after antigen challenge. BAL was more enriched in fibronectin 48 h after challenge than would be predicted solely from increased permeability of plasma proteins. Western blot analysis showed that fibronectin in BAL fluid was largely intact and contained the extra domain-A (ED-A) splice variant of cellular fibronectin, indicative of local production. We conclude that antigen challenge in atopic subjects causes increased production of fibronectin by airway cells and speculate that this response may contribute to airway remodeling in allergic inflammation.     

Achieving and maintaining compliance with the ketogenic diet

The ketogenic diet, a treatment for intractable epilepsy, is rarely initiated because it requires strict compliance with a diet that is perceived to be unpalatable. In a case study of a 15-year-old girl with uncontrolled epilepsy, we used a stimulus-choice procedure to assess relative preferences of 33 foods from the diet and to develop two treatments based on Premack's principle. The results of a multielement analysis showed that both treatments increased dietary compliance. Compliance was maintained with generalization of treatment across settings, and was associated with a 40% reduction in seizures.     

Captopril modifies gene expression in hypertrophied and failing hearts of aged spontaneously hypertensive rats

The spontaneously hypertensive rat (SHR) exhibits a transition from stable compensated left ventricular (LV) hypertrophy to heart failure (HF) at a mean age of 21 months that is characterized by a decrease in alpha-myosin heavy chain (alpha-MHC) gene expression and increases in the expression of the atrial natriuretic factor (ANF), pro-alpha1(III) collagen, and transforming growth factor beta1 (TGF-beta1) genes. We tested the hypotheses that angiotensin-converting enzyme inhibition (ACEI) in SHR would prevent and reverse HF-associated changes in gene expression when administered prior to and after the onset of HF, respectively. We also investigated the effect of ACEI on circulating and cardiac components of the renin-angiotensin system. ACEI (captopril 2 g/L in the drinking water) was initiated at 12, 18, and 21 months of age in SHR without HF and in SHR with HF. Results were compared with those of age-matched normotensive Wistar-Kyoto (WKY) rats, and to untreated SHR with and without evidence of HF. ACEI initiated prior to failure prevented the changes in alpha-MHC, ANF, pro-alpha1(III) collagen, and TGF-beta1 gene expression that are associated with the transition to HF. ACEI initiated after the onset of HF lowered levels of TGF-beta1 mRNA by 50% (P<.05) and elevated levels of alpha-MHC mRNA two- to threefold (P<.05). Circulating levels of renin and angiotensin I were elevated four- to sixfold by ACEI, but surprisingly, plasma levels of angiotensin II were not reduced. ACEI increased LV renin mRNA levels in WKY and SHR by two- to threefold but did not influence LV levels of angiotensinogen mRNA. The results suggest that the anti-HF benefits of ACEI in SHR may be mediated, at least in part, by effects on the expression of specific genes, including those encoding alpha-MHC, ANF, TGF-beta1, pro-alpha1(III) collagen, and renin-angiotensin system components.     

Transgene expression of bcl-xL permits anti-immunoglobulin (Ig)-induced proliferation in xid B cells

Mutations in the tyrosine kinase, Btk, result in a mild immunodeficiency in mice (xid). While B lymphocytes from xid mice do not proliferate to anti-immunoglobulin (Ig), we show here induction of the complete complement of cell cycle regulatory molecules, though the level of induction is about half that detected in normal B cells. Cell cycle analysis reveals that anti-Ig stimulated xid B cells enter S phase, but fail to complete the cell cycle, exhibiting a high rate of apoptosis. This correlated with a decreased ability to induce the anti-apoptosis regulatory protein, Bcl-xL. Ectopic expression of Bcl-xL in xid B cells permitted anti-Ig induced cell cycle progression demonstrating dual requirements for induction of anti-apoptotic proteins plus cell cycle regulatory proteins during antigen receptor mediated proliferation. Furthermore, our results link one of the immunodeficient traits caused by mutant Btk with the failure to properly regulate Bcl-xL.     

Magnetic resonance imaging scanning in the diagnosis of zone II flexor tendon rupture

This study was undertaken to determine the usefulness of magnetic resonance imaging (MRI) in the diagnosis of flexor tendon rupture in patients who had prior surgery. Magnetic resonance imaging scans were performed on 11 digits (16 tendons) with the clinical diagnosis of flexor tendon rupture. Clinical suspicion correlated with MRI and surgical findings. Clinical examination yielded a 60% accuracy in diagnosis. MRI differentiated rupture from adhesions with a 100% accuracy rate. The MRI scan is a valuable tool in diagnosing tendon ruptures and may help reduce the incidence of unnecessary tendon explorations.     

Clinic characteristics associated with reduced hospitalization of drug users with AIDS

The purpose of this study was to develop a substantive grounded theory of courage among middle-aged adults with long-term health concerns. Twenty-five persons from rural and non-metropolitan areas of Central Illinois were selected to participate in this study based on theoretical sampling procedures. Interviews of 1 to 2 hours using openended questions were audiotaped and transcribed verbatim. The data were analysed using grounded theory methods. Courage among middle-aged adults with long-term health concerns was determined to consist of an ongoing progressive-regressive process of becoming and being courageous. Being courageous involves being fully aware of and accepting the threat of a long-term health concern, solving problems using discernment, and developing enhanced sensitivities to personal needs and the world in general. Courageous behaviour consists of taking responsibility and being productive. Courage is not limitless, and the process of becoming and being courageous is dependent on intrapersonal and interpersonal factors. Health-care providers facilitate this process by demonstrating competence and communicating effectively. Outcomes of being courageous include personal integrity and thriving in the midst of normality.     

The prevention pill

Eight children with the cyst of choledochus, ageing from 1 month to 15 years, were treated for the period of 20 years in clinic. Cystoduodenostomy is the method of choice for the treatment. All the patients have recovered.