Characterization of two mouse models of metastatic pheochromocytoma using bioluminescence imaging

Pheochromocytoma is the most common tumor of the adrenal medulla in adults. The lack of sensitive animal models of pheochromocytoma has hindered the study of this tumor and in vivo evaluation of antitumor agents. In this study we generated two sensitive luciferase models using bioluminescent pheochromocytoma cells: an experimental metastasis model to monitor tumor spreading and a subcutaneous model to monitor tumor growth and spontaneous metastasis. These models offer a platform for sensitive, non-invasive and real-time monitoring of pheochromocytoma primary growth and metastatic burden to follow the course of tumor progression and for testing relevant antitumor treatments in metastatic pheochromocytoma.     

Stress responsivity and HPA axis activity in juveniles: results from a home-based CO2 inhalation study

OBJECTIVE: A previous laboratory-based study found elevated cortisol levels in anxious children susceptible to CO(2)-induced panic, but the effects of parent diagnosis were not considered. The current home-based study tested the hypothesis that parental panic disorder and offspring response to CO(2) are associated with elevated cortisol levels in juvenile offspring. METHOD: A total of 131 offspring (ages 9-19) of parents with panic disorder, major depression, and no mental disorder underwent CO(2) inhalation. Parent and child diagnoses were assessed. Salivary cortisol was assayed before and after CO(2) inhalation. RESULTS: Neither parents with panic disorder, parents with major depression, or offspring anxiety predicted offspring cortisol levels. Independent of parent and child diagnoses, anxiety response to CO(2) predicted elevated cortisol levels in offspring. CONCLUSIONS: As in adults, anxiety response to CO(2) in juveniles is associated with elevated cortisol levels, but elevated cortisol levels are not related to parent or child diagnoses.     

Stent Migration and Folding in the Subclavian Vein during Subclavian Hemodialysis Catheter Placement

The role of stent placement in hemodialysis (HD) access intervention continues to evolve. As more stents are placed, new and unusual complications are coming to light. We describe a case in which an unsuccessful attempt to place a left subclavian dialysis catheter resulted in the inadvertent migration and folding of a previously deployed subclavian stent. Attempts to remove the stent with a snare were unsuccessful. Patency was restored to the access circuit by placing a new stent through the struts of the folded one. Clinical vascular practice guidelines for vascular access on the use of fluoroscopy for temporary HD catheter placement may need to be re-evaluated with the reported increase in stent placement in the US HD population.     

A review of the neuropharmacological properties of khat

BACKGROUND: The psychostimulant khat (Catha edulis Forsk), is a herbal drug cultivated and chewed as a recreational and socializing drug in East Africa and the Arabian Peninsula for centuries. Due to increasing air transportation and the loosening of customs restrictions, it is now readily available in the Western Countries mainly used by immigrants from khat growing areas causing a concern to policy-makers. OBJECTIVE: We conducted this review to further gain an insight to the neuropharmacological effects of khat. METHODOLOGY: PubMed search engine with key terms 'khat' or 'qat' or 'mirra' or'qaad/jaad' or 'cathinone' was used to obtain articles relevant to khat chewing. In total 284 English written articles published from 1959 to 2007 were screened. RESULTS: Most of the studies focused on cathinone, the postulated active psychostimulant alkaloid in khat. There were few studies which investigated the entire plant extract in either in vitro or animal studies. In the majority of the studies it was reported that both cathinone and cathine, another psychoactive constituent, have actions that are similar to those of amphetamine. CONCLUSIONS: It seems that the well investigated khat alkaloids have many features similar to amphetamines; however there is a need for a more thorough examination of khat itself in well designed in vitro, animal and human studies with a range of comparator drugs before confirming the claim that khat is a "natural amphetamine".     

Estimation of the von Willebrand factor-cleaving protease in plasma using monoclonal antibodies to vWF

A protease present in plasma cleaves von Willebrand factor (vWF) at the peptide bond 842Tyr-843Met of the mature subunit. To quantify this vWF-cleaving protease activity in plasma we have developed a simple method based on the estimation by IRMA of the degradation of a constant amount of wild type recombinant vWF used as substrate, by serial dilutions of test plasma used as protease provider. vWFAg was estimated by two-site IRMA using as first coating antibody a monoclonal antibody (MoAb) whose epitope is localized on the C-terminal side of the cleavage site, and as second labeled antibody a pool of MoAbs specific for the N-terminal side. Because the proteolytic process leads to the progressive separation of the C- and N-terminal portions of the vWF subunit such an IRMA also shows a progressive apparent loss of vWFAg. In contrast, the levels of vWFAg estimated after proteolysis by regular IRMA remained essentially constant. Results obtained with this new method were compared with the analysis by SDS-agarose gel electrophoresis of the multimeric pattern of proteolyzed WT-rvWF and no significant difference was noted testing a series of 28 plasmas. As compared with normal pooled plasma, 14 normal individuals and 13 patients with various types of vWD had normal levels of protease activity (44-178%) by both methods. The validity of the method was confirmed by showing a lack of detectable protease activity in a patient with chronic relapsing thrombotic thrombocytopenic purpura. In conclusion our method appears as a useful tool for the quantification of the vWF-cleaving protease activity in plasma. Its sensitivity and specificity are similar to those of SDS-gel electrophoresis. However, this new IRMA has the major advantages of being much simpler and faster, and open to most research laboratories in the field.     

Response to 5% carbon dioxide in children and adolescents: relationship to panic disorder in parents and anxiety disorders in subjects

BACKGROUND: Carbon dioxide (CO(2)) sensitivity is postulated to be a familial risk marker of panic disorder (PD). Exaggerated responses to CO(2) inhalation have been reported in adults with PD and their unaffected adult relatives, as well as in clinic-referred children with anxiety disorders. OBJECTIVE: To test in a family-based design whether CO(2) hypersensitivity is a familial risk marker for PD and associated with current anxiety disorders in children and adolescents. SETTING AND PARTICIPANTS: One hundred forty-two offspring (aged 9-19 years) of parents with PD, major depressive disorder, or no disorder. Forty-five (32%) had a current anxiety disorder, excluding specific phobia. DESIGN AND MAIN OUTCOME MEASURES: Parents and offspring received diagnostic assessments. Offspring underwent 5% CO(2) inhalation at home. Panic symptoms and panic attacks were rated with the Acute Panic Inventory at baseline, while anticipating CO(2) delivery ("threat"), and during CO(2) inhalation. Respiratory rate and volume were measured with spirometry. RESULTS: No group differences were found in Acute Panic Inventory ratings at baseline or in respiratory measures during threat. Risk for PD was not associated with CO(2) sensitivity (panic symptoms and respiratory physiologic response). During CO(2) inhalation, offspring with anxiety disorders, relative to offspring without anxiety disorders, experienced significantly more panic symptoms and panic attacks, as well as elevated respiratory rates. During threat, panic symptoms were significantly and independently associated with both parental PD and offspring anxiety disorders. CONCLUSIONS: No support was obtained for CO(2) hypersensitivity as a familial risk marker for PD in children and adolescents. Links between childhood anxiety disorders and CO(2) sensitivity were replicated. Familial risk for PD in children and adolescents may be associated with vulnerability to anticipatory anxiety.     

Triage of atypical squamous cells of undetermined significance with hybrid capture II: colposcopy and histologic human papillomavirus correlation

OBJECTIVE: To estimate the effectiveness of Hybrid Capture II to predict high-grade cervical intraepithelial neoplasia (CIN) from a cytological cervical sample. Evidence of high-risk human papillomavirus (HPV) was also determined from biopsy samples using the polymerase chain reaction (PCR) for women referred with atypical squamous cells of undetermined significance (ASCUS) Papanicolaou smears. METHODS: We screened 8170 women with Papanicolaou smears, of whom 278 (3.4%) returned ASCUS. All ASCUS cases underwent colposcopy and Hybrid Capture II testing. High-grade CIN biopsy specimens were tested for high-risk HPV by PCR. RESULTS: Nearly 30% of ASCUS cases had CIN biopsy results (11.9% showing CIN II or CIN III and 17.6% showing CIN I). Hybrid Capture II positive rates were 93.3% for cases with CIN III, 72.2% for CIN II, and 51.0% for CIN I (P <.001). ASCUS-Premalignant Process Favored cases showed a 28.1% high-grade biopsy rate and a 100% Hybrid Capture II positive rate. For ASCUS-Undefined and ASCUS-Reactive Process Favored cases, Hybrid Capture II returned positive in 90.9% of CIN III and 61.5% of CIN II cases (P <.001). Sixty-nine of 178 (38.8%) patients with no evidence of CIN tested positive for Hybrid Capture II. Human papillomavirus deoxyribonucleic acid (DNA) high-risk subtypes were detected by PCR in the tissue of all high-grade CIN cases with negative Hybrid Capture II results. CONCLUSION: Hybrid Capture II returned negative in 25% of cases with biopsy-proven high-grade CIN with associated high-risk HPV DNA by PCR (non-Premalignant ASCUS subset), and positive in 39.3% of cases with normal results; this limits its clinical utility.     

Antibacterial diterpenes from Calceolaria pinifolia

Two new isopimaranes, 19-methylmalonyloxy-ent-isopimara-8(9),15-diene (5) and 19-malonyloxy-ent-isopimara-8(9),15-diene (6), were isolated using bioassay-guided fractionation of the CH(2)Cl(2)-MeOH (1:1) extract of the aerial part of Calceolaria pinifolia along with eight other diterpenes (1-4, 7-10) and two triterpenes (11, 12). All compounds were assayed against Staphylococcus aureus (SA), methicillin-resistant S. aureus (MRSA), Bacillus subtilis (BS), and Escherichia coli (EC). 4-Epi-dehydroabietinol (2) and ent-isopimara-9(11),15-diene-19-ol (8) were found to be active against MRSA with MIC values of 8 and 2 microgram/mL, respectively. Mechanistic studies of 8 in BS suggested rapid and nonspecific inhibition of uptake and incorporation of radiolabeled precursors into DNA, RNA, and protein consistent with membrane-damaging effects in bacteria. Compound 8 did not afford protection against an acute infection with SA in mice.     

Development of a nucleic acid sequence-based amplification assay that uses gag-based molecular beacons to distinguish between human immunodeficiency virus type 1 subtype C and C' infections in Ethiopia

A gag-based molecular beacon assay utilizing real-time nucleic acid sequence-based amplification technology has been developed to differentiate between the two genetic subclusters of human immunodeficiency virus type 1 (HIV-1) subtype C (C and C') circulating in Ethiopia. Of 41 samples, 36 could be classified as C or C' by sequencing of the gag gene. All 36 isolates were correctly identified by the gag beacon test. Three isolates with genomes that were recombinant in gag were unambiguously typed as belonging to the C' subcluster. Further analysis revealed that these contained the most sequence homology with a reference subcluster C' sequence in the target region of the beacon and hence were correct for the analyzed region. For one sample, sequencing and gag molecular beacon results did not match, while another isolate could not be detected at all by the beacon assay. Overall, high levels of sensitivity and specificity were achieved for both beacons (90.5% sensitivity and 100% specificity for the C beacon and 100% sensitivity and 95.2% specificity for the C' beacon). The availability of a diagnostic test which can quickly and reliably discriminate between C and C' HIV-1 infections in Ethiopia is an important first step toward studying their respective biological characteristics. As the assay is specific to the Ethiopian HIV-1 subtype C epidemic, it will contribute to characterizing the circulating viruses in this population, thereby generating the information necessary for the development of a potential efficacious HIV-1 vaccine appropriate for the Ethiopian context.